From 3b5d73f5cee0921c692e53e5b1e6489a61e8faa9 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Tue, 16 Jun 2015 12:13:18 -0700
Subject: [PATCH 1/3] Use Object.create(null) in __extends when base is null

---
 src/compiler/emitter.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 8081668f98..5181a0f17f 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -21,8 +21,7 @@ namespace ts {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };`;
 
         // emit output for the __decorate helper function

From 835f91137c47ed08db90d876359cc735212af73d Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Tue, 16 Jun 2015 12:18:31 -0700
Subject: [PATCH 2/3] Accepting new baselines

---
 ...sClassHeritageListMemberTypeAnnotations.js |   3 +-
 ...accessibleTypeInTypeParameterConstraint.js |   3 +-
 .../accessOverriddenBaseClassMember1.js       |   3 +-
 .../accessors_spec_section-4.5_inference.js   |   3 +-
 .../reference/aliasUsageInAccessorsOfClass.js |   3 +-
 .../baselines/reference/aliasUsageInArray.js  |   3 +-
 .../aliasUsageInFunctionExpression.js         |   3 +-
 .../reference/aliasUsageInGenericFunction.js  |   3 +-
 .../reference/aliasUsageInIndexerOfClass.js   |   3 +-
 .../reference/aliasUsageInObjectLiteral.js    |   3 +-
 .../reference/aliasUsageInOrExpression.js     |   3 +-
 ...aliasUsageInTypeArgumentOfExtendsClause.js |   6 +-
 .../reference/aliasUsageInVarAssignment.js    |   3 +-
 .../reference/ambiguousOverloadResolution.js  |   3 +-
 .../reference/apparentTypeSubtyping.js        |   3 +-
 .../reference/apparentTypeSupertype.js        |   3 +-
 .../reference/arrayAssignmentTest1.js         |   3 +-
 .../reference/arrayAssignmentTest2.js         |   3 +-
 .../reference/arrayBestCommonTypes.js         |   3 +-
 .../reference/arrayLiteralTypeInference.js    |   3 +-
 tests/baselines/reference/arrayLiterals.js    |   3 +-
 .../arrayLiteralsWithRecursiveGenerics.js     |   3 +-
 .../reference/arrowFunctionContexts.js        |   3 +-
 .../assignmentCompatWithCallSignatures3.js    |   3 +-
 .../assignmentCompatWithCallSignatures4.js    |   3 +-
 .../assignmentCompatWithCallSignatures5.js    |   3 +-
 .../assignmentCompatWithCallSignatures6.js    |   3 +-
 ...ssignmentCompatWithConstructSignatures3.js |   3 +-
 ...ssignmentCompatWithConstructSignatures4.js |   3 +-
 ...ssignmentCompatWithConstructSignatures5.js |   3 +-
 ...ssignmentCompatWithConstructSignatures6.js |   3 +-
 .../assignmentCompatWithNumericIndexer.js     |   3 +-
 .../assignmentCompatWithNumericIndexer3.js    |   3 +-
 .../assignmentCompatWithObjectMembers4.js     |   3 +-
 ...nmentCompatWithObjectMembersOptionality.js |   3 +-
 ...mentCompatWithObjectMembersOptionality2.js |   3 +-
 .../assignmentCompatWithStringIndexer.js      |   3 +-
 .../reference/assignmentLHSIsValue.js         |   3 +-
 tests/baselines/reference/autolift4.js        |   3 +-
 tests/baselines/reference/baseCheck.js        |   3 +-
 .../reference/baseIndexSignatureResolution.js |   3 +-
 .../reference/baseTypeOrderChecking.js        |   3 +-
 .../baseTypeWrappingInstantiationChain.js     |   3 +-
 tests/baselines/reference/bases.js            |   3 +-
 .../bestCommonTypeOfConditionalExpressions.js |   3 +-
 ...bestCommonTypeOfConditionalExpressions2.js |   3 +-
 .../reference/bestCommonTypeOfTuple2.js       |   3 +-
 ...allSignatureAssignabilityInInheritance2.js |   3 +-
 ...allSignatureAssignabilityInInheritance3.js |   3 +-
 ...allSignatureAssignabilityInInheritance4.js |   3 +-
 ...allSignatureAssignabilityInInheritance5.js |   3 +-
 ...allSignatureAssignabilityInInheritance6.js |   3 +-
 tests/baselines/reference/callWithSpread.js   |   3 +-
 .../reference/captureThisInSuperCall.js       |   3 +-
 tests/baselines/reference/castingTuple.js     |   3 +-
 .../baselines/reference/chainedAssignment3.js |   3 +-
 ...arameterConstrainedToOtherTypeParameter.js |   3 +-
 .../reference/checkForObjectTooStrict.js      |   3 +-
 .../reference/circularImportAlias.js          |   3 +-
 ...classConstructorParametersAccessibility.js |   3 +-
 ...lassConstructorParametersAccessibility2.js |   3 +-
 ...lassConstructorParametersAccessibility3.js |   3 +-
 ...clarationMergedInModuleWithContinuation.js |   3 +-
 .../classDoesNotDependOnBaseTypes.js          |   3 +-
 .../reference/classExtendingClass.js          |   3 +-
 .../reference/classExtendingPrimitive.js      |   3 +-
 .../reference/classExtendingPrimitive2.js     |   3 +-
 .../reference/classExtendingQualifiedName.js  |   3 +-
 .../reference/classExtendingQualifiedName2.js |   3 +-
 ...sMergedWithModuleNotReferingConstructor.js |   3 +-
 ...tendsClauseClassNotReferringConstructor.js |   3 +-
 .../reference/classExtendsEveryObjectType.js  |   3 +-
 .../reference/classExtendsEveryObjectType2.js |   3 +-
 .../reference/classExtendsInterface.js        |   3 +-
 .../baselines/reference/classExtendsItself.js |   3 +-
 .../reference/classExtendsItselfIndirectly.js |   3 +-
 .../classExtendsItselfIndirectly2.js          |   3 +-
 .../classExtendsItselfIndirectly3.js          |  18 +-
 .../classExtendsMultipleBaseClasses.js        |   3 +-
 ...classExtendsShadowedConstructorFunction.js |   3 +-
 .../classExtendsValidConstructorFunction.js   |   3 +-
 .../classHeritageWithTrailingSeparator.js     |   3 +-
 .../reference/classImplementsClass2.js        |   3 +-
 .../reference/classImplementsClass3.js        |   3 +-
 .../reference/classImplementsClass4.js        |   3 +-
 .../reference/classImplementsClass5.js        |   3 +-
 .../reference/classImplementsClass6.js        |   3 +-
 tests/baselines/reference/classIndexer3.js    |   3 +-
 tests/baselines/reference/classInheritence.js |   3 +-
 .../reference/classIsSubtypeOfBaseType.js     |   3 +-
 tests/baselines/reference/classOrder2.js      |   3 +-
 tests/baselines/reference/classOrderBug.js    |   3 +-
 .../reference/classSideInheritance1.js        |   3 +-
 .../reference/classSideInheritance2.js        |   3 +-
 .../reference/classSideInheritance3.js        |   3 +-
 tests/baselines/reference/classUpdateTests.js |   3 +-
 .../classWithBaseClassButNoConstructor.js     |   3 +-
 .../reference/classWithConstructors.js        |   3 +-
 .../reference/classWithProtectedProperty.js   |   3 +-
 .../reference/classWithStaticMembers.js       |   3 +-
 tests/baselines/reference/classdecl.js        |   3 +-
 .../reference/clodulesDerivedClasses.js       |   3 +-
 ...llisionSuperAndLocalFunctionInAccessors.js |   3 +-
 ...isionSuperAndLocalFunctionInConstructor.js |   3 +-
 .../collisionSuperAndLocalFunctionInMethod.js |   3 +-
 ...ollisionSuperAndLocalFunctionInProperty.js |   3 +-
 .../collisionSuperAndLocalVarInAccessors.js   |   3 +-
 .../collisionSuperAndLocalVarInConstructor.js |   3 +-
 .../collisionSuperAndLocalVarInMethod.js      |   3 +-
 .../collisionSuperAndLocalVarInProperty.js    |   3 +-
 .../collisionSuperAndNameResolution.js        |   3 +-
 .../reference/collisionSuperAndParameter.js   |   3 +-
 .../reference/collisionSuperAndParameter1.js  |   3 +-
 ...perAndPropertyNameAsConstuctorParameter.js |   3 +-
 ...xpressionAndLocalVarWithSuperExperssion.js |   3 +-
 .../reference/commentsInheritance.js          |   3 +-
 .../comparisonOperatorWithIdenticalObjects.js |   3 +-
 ...ithNoRelationshipObjectsOnCallSignature.js |   3 +-
 ...lationshipObjectsOnConstructorSignature.js |   3 +-
 ...thNoRelationshipObjectsOnIndexSignature.js |   3 +-
 ...nshipObjectsOnInstantiatedCallSignature.js |   3 +-
 ...jectsOnInstantiatedConstructorSignature.js |   3 +-
 ...peratorWithSubtypeObjectOnCallSignature.js |   3 +-
 ...WithSubtypeObjectOnConstructorSignature.js |   3 +-
 ...eratorWithSubtypeObjectOnIndexSignature.js |   3 +-
 ...ubtypeObjectOnInstantiatedCallSignature.js |   3 +-
 ...bjectOnInstantiatedConstructorSignature.js |   3 +-
 ...isonOperatorWithSubtypeObjectOnProperty.js |   3 +-
 .../reference/complexClassRelationships.js    |   3 +-
 ...catedGenericRecursiveBaseClassReference.js |   3 +-
 .../reference/compoundAssignmentLHSIsValue.js |   3 +-
 .../reference/computedPropertyNames24_ES5.js  |   3 +-
 .../reference/computedPropertyNames25_ES5.js  |   3 +-
 .../reference/computedPropertyNames26_ES5.js  |   3 +-
 .../reference/computedPropertyNames27_ES5.js  |   3 +-
 .../reference/computedPropertyNames28_ES5.js  |   3 +-
 .../reference/computedPropertyNames30_ES5.js  |   3 +-
 .../reference/computedPropertyNames31_ES5.js  |   3 +-
 .../reference/computedPropertyNames43_ES5.js  |   3 +-
 .../reference/computedPropertyNames44_ES5.js  |   3 +-
 .../reference/computedPropertyNames45_ES5.js  |   3 +-
 .../conditionalOperatorWithIdenticalBCT.js    |   3 +-
 .../conditionalOperatorWithoutIdenticalBCT.js |   3 +-
 .../reference/constantOverloadFunction.js     |   3 +-
 .../constantOverloadFunctionNoSubtypeError.js |   3 +-
 ...nstraintCheckInGenericBaseTypeReference.js |   3 +-
 ...uctSignatureAssignabilityInInheritance2.js |   3 +-
 ...uctSignatureAssignabilityInInheritance3.js |   3 +-
 ...uctSignatureAssignabilityInInheritance4.js |   3 +-
 ...uctSignatureAssignabilityInInheritance5.js |   3 +-
 ...uctSignatureAssignabilityInInheritance6.js |   3 +-
 tests/baselines/reference/constructorArgs.js  |   3 +-
 ...uctorFunctionTypeIsAssignableToBaseType.js |   3 +-
 ...ctorFunctionTypeIsAssignableToBaseType2.js |   3 +-
 .../constructorHasPrototypeProperty.js        |   3 +-
 .../reference/constructorOverloads2.js        |   3 +-
 .../reference/constructorOverloads3.js        |   3 +-
 ...constructorWithIncompleteTypeAnnotation.js |   3 +-
 .../contextualTypingArrayOfLambdas.js         |   3 +-
 ...contextualTypingOfConditionalExpression.js |   3 +-
 ...ontextualTypingOfConditionalExpression2.js |   3 +-
 ...urcePropertyIsRelatableToTargetProperty.js |   3 +-
 .../declFileForFunctionTypeAsTypeParameter.js |   3 +-
 ...ileGenericClassWithGenericExtendedClass.js |   3 +-
 .../reference/declFileGenericType.js          |   3 +-
 .../reference/declFileGenericType2.js         |   3 +-
 ...lictingWithClassReferredByExtendsClause.js |   3 +-
 ...dsClauseThatHasItsContainerNameConflict.js |   3 +-
 .../declarationEmit_nameConflicts3.js         |   3 +-
 .../declarationEmit_protectedMembers.js       |   3 +-
 .../reference/declareDottedExtend.js          |   3 +-
 .../reference/decoratorOnClassMethod12.js     |   3 +-
 ...derivedClassConstructorWithoutSuperCall.js |   3 +-
 ...ClassFunctionOverridesBaseClassAccessor.js |   3 +-
 .../derivedClassIncludesInheritedMembers.js   |   3 +-
 ...idesIndexersWithAssignmentCompatibility.js |   3 +-
 .../derivedClassOverridesPrivateFunction1.js  |   3 +-
 .../derivedClassOverridesPrivates.js          |   3 +-
 .../derivedClassOverridesProtectedMembers.js  |   3 +-
 .../derivedClassOverridesProtectedMembers2.js |   3 +-
 .../derivedClassOverridesProtectedMembers3.js |   3 +-
 .../derivedClassOverridesProtectedMembers4.js |   3 +-
 .../derivedClassOverridesPublicMembers.js     |   3 +-
 .../derivedClassOverridesWithoutSubtype.js    |   3 +-
 .../derivedClassParameterProperties.js        |   3 +-
 ...dClassSuperCallsInNonConstructorMembers.js |   3 +-
 .../derivedClassSuperCallsWithThisArg.js      |   3 +-
 .../reference/derivedClassTransitivity.js     |   3 +-
 .../reference/derivedClassTransitivity2.js    |   3 +-
 .../reference/derivedClassTransitivity3.js    |   3 +-
 .../reference/derivedClassTransitivity4.js    |   3 +-
 .../reference/derivedClassWithAny.js          |   3 +-
 ...ivateInstanceShadowingProtectedInstance.js |   3 +-
 ...hPrivateInstanceShadowingPublicInstance.js |   3 +-
 ...thPrivateStaticShadowingProtectedStatic.js |   3 +-
 ...sWithPrivateStaticShadowingPublicStatic.js |   3 +-
 .../derivedClassWithoutExplicitConstructor.js |   3 +-
 ...derivedClassWithoutExplicitConstructor2.js |   3 +-
 ...derivedClassWithoutExplicitConstructor3.js |   3 +-
 tests/baselines/reference/derivedClasses.js   |   3 +-
 .../reference/derivedGenericClassWithAny.js   |   3 +-
 ...sesHiddenBaseCallViaSuperPropertyAccess.js |   3 +-
 .../derivedTypeDoesNotRequireExtendsClause.js |   3 +-
 .../destructuringParameterDeclaration5.js     |   3 +-
 .../reference/emitThisInSuperMethodCall.js    |   3 +-
 ...rorForwardReferenceForwadingConstructor.js |   3 +-
 tests/baselines/reference/errorSuperCalls.js  |   3 +-
 .../reference/errorSuperPropertyAccess.js     |   3 +-
 .../reference/errorsInGenericTypeReference.js |   3 +-
 .../reference/es6ClassSuperCodegenBug.js      |   3 +-
 tests/baselines/reference/es6ClassTest.js     |   3 +-
 tests/baselines/reference/es6ClassTest2.js    |   3 +-
 tests/baselines/reference/es6ClassTest7.js    |   3 +-
 .../exportAssignmentOfGenericType1.js         |   3 +-
 .../exportDeclarationInInternalModule.js      |   3 +-
 tests/baselines/reference/extBaseClass1.js    |   3 +-
 tests/baselines/reference/extBaseClass2.js    |   3 +-
 .../extendAndImplementTheSameBaseType.js      |   3 +-
 .../extendAndImplementTheSameBaseType2.js     |   3 +-
 .../extendBaseClassBeforeItsDeclared.js       |   3 +-
 .../reference/extendNonClassSymbol1.js        |   3 +-
 .../reference/extendNonClassSymbol2.js        |   3 +-
 ...xtendingClassFromAliasAndUsageInIndexer.js |   6 +-
 .../reference/extendsClauseAlreadySeen.js     |   3 +-
 .../reference/extendsClauseAlreadySeen2.js    |   3 +-
 tests/baselines/reference/for-inStatements.js |   3 +-
 .../reference/for-inStatementsInvalid.js      |   3 +-
 .../forStatementsMultipleInvalidDecl.js       |   3 +-
 .../reference/functionImplementationErrors.js |   3 +-
 .../reference/functionImplementations.js      |   3 +-
 .../reference/functionSubtypingOfVarArgs.js   |   3 +-
 .../reference/functionSubtypingOfVarArgs2.js  |   3 +-
 .../reference/generatedContextualTyping.js    |   3 +-
 .../genericBaseClassLiteralProperty.js        |   3 +-
 .../genericBaseClassLiteralProperty2.js       |   3 +-
 ...allWithConstraintsTypeArgumentInference.js |   3 +-
 .../genericCallWithObjectTypeArgs2.js         |   3 +-
 ...icCallWithObjectTypeArgsAndConstraints2.js |   3 +-
 ...icCallWithObjectTypeArgsAndConstraints3.js |   3 +-
 .../genericCallbacksAndClassHierarchy.js      |   3 +-
 ...sInheritsConstructorFromNonGenericClass.js |   3 +-
 ...cClassPropertyInheritanceSpecialization.js |   3 +-
 .../reference/genericClassStaticMethod.js     |   3 +-
 tests/baselines/reference/genericClasses3.js  |   3 +-
 ...genericConstraintOnExtendedBuiltinTypes.js |   3 +-
 ...enericConstraintOnExtendedBuiltinTypes2.js |   3 +-
 .../genericDerivedTypeWithSpecializedBase.js  |   3 +-
 .../genericDerivedTypeWithSpecializedBase2.js |   3 +-
 .../reference/genericPrototypeProperty2.js    |   3 +-
 .../reference/genericPrototypeProperty3.js    |   3 +-
 ...ericRecursiveImplicitConstructorErrors2.js |   3 +-
 ...ericRecursiveImplicitConstructorErrors3.js |   3 +-
 .../reference/genericTypeAssertions2.js       |   3 +-
 .../reference/genericTypeAssertions4.js       |   3 +-
 .../reference/genericTypeAssertions6.js       |   3 +-
 .../reference/genericTypeConstraints.js       |   3 +-
 ...genericTypeReferenceWithoutTypeArgument.js |   3 +-
 ...enericTypeReferenceWithoutTypeArgument2.js |   3 +-
 .../genericWithIndexerOfTypeParameterType2.js |   3 +-
 .../reference/heterogeneousArrayLiterals.js   |   3 +-
 .../reference/ifDoWhileStatements.js          |   3 +-
 .../illegalSuperCallsInConstructor.js         |   3 +-
 .../implementClausePrecedingExtends.js        |   3 +-
 ...gAnInterfaceExtendingClassWithPrivates2.js |   3 +-
 ...AnInterfaceExtendingClassWithProtecteds.js |   3 +-
 .../baselines/reference/importAsBaseClass.js  |   3 +-
 .../reference/importShadowsGlobalName.js      |   3 +-
 .../reference/importUsedInExtendsList1.js     |   3 +-
 .../reference/indexerConstraints2.js          |   3 +-
 .../reference/indirectSelfReference.js        |   3 +-
 .../reference/indirectSelfReferenceGeneric.js |   3 +-
 .../infinitelyExpandingTypesNonGenericBase.js |   3 +-
 .../inheritFromGenericTypeParameter.js        |   3 +-
 ...SameNamePrivatePropertiesFromSameOrigin.js |   3 +-
 tests/baselines/reference/inheritance.js      |   3 +-
 tests/baselines/reference/inheritance1.js     |   3 +-
 ...itanceGrandParentPrivateMemberCollision.js |   3 +-
 ...tPrivateMemberCollisionWithPublicMember.js |   3 +-
 ...tPublicMemberCollisionWithPrivateMember.js |   3 +-
 ...ritanceMemberAccessorOverridingAccessor.js |   3 +-
 ...heritanceMemberAccessorOverridingMethod.js |   3 +-
 ...ritanceMemberAccessorOverridingProperty.js |   3 +-
 ...inheritanceMemberFuncOverridingAccessor.js |   3 +-
 .../inheritanceMemberFuncOverridingMethod.js  |   3 +-
 ...inheritanceMemberFuncOverridingProperty.js |   3 +-
 ...ritanceMemberPropertyOverridingAccessor.js |   3 +-
 ...heritanceMemberPropertyOverridingMethod.js |   3 +-
 ...ritanceMemberPropertyOverridingProperty.js |   3 +-
 .../inheritanceOfGenericConstructorMethod1.js |   3 +-
 .../inheritanceOfGenericConstructorMethod2.js |   3 +-
 ...ritanceStaticAccessorOverridingAccessor.js |   3 +-
 ...heritanceStaticAccessorOverridingMethod.js |   3 +-
 ...ritanceStaticAccessorOverridingProperty.js |   3 +-
 ...inheritanceStaticFuncOverridingAccessor.js |   3 +-
 ...eStaticFuncOverridingAccessorOfFuncType.js |   3 +-
 .../inheritanceStaticFuncOverridingMethod.js  |   3 +-
 ...inheritanceStaticFuncOverridingProperty.js |   3 +-
 ...eStaticFuncOverridingPropertyOfFuncType.js |   3 +-
 ...taticFunctionOverridingInstanceProperty.js |   3 +-
 .../inheritanceStaticMembersCompatible.js     |   3 +-
 .../inheritanceStaticMembersIncompatible.js   |   3 +-
 ...ritanceStaticPropertyOverridingAccessor.js |   3 +-
 ...heritanceStaticPropertyOverridingMethod.js |   3 +-
 ...ritanceStaticPropertyOverridingProperty.js |   3 +-
 .../inheritedConstructorWithRestParams.js     |   3 +-
 .../inheritedConstructorWithRestParams2.js    |   3 +-
 .../inheritedModuleMembersForClodule.js       |   3 +-
 ...nstancePropertiesInheritedIntoClassType.js |   3 +-
 .../reference/instanceSubtypeCheck2.js        |   3 +-
 .../instantiatedReturnTypeContravariance.js   |   3 +-
 .../reference/interfaceExtendsClass1.js       |   3 +-
 .../interfaceExtendsClassWithPrivate1.js      |   3 +-
 .../interfaceExtendsClassWithPrivate2.js      |   3 +-
 .../reference/interfaceImplementation8.js     |   3 +-
 .../invalidModuleWithStatementsOfEveryKind.js |   3 +-
 .../invalidMultipleVariableDeclarations.js    |   3 +-
 .../reference/invalidReturnStatements.js      |   3 +-
 .../isolatedModulesImportExportElision.js     |   3 +-
 tests/baselines/reference/lambdaArgCrash.js   |   3 +-
 tests/baselines/reference/lift.js             |   3 +-
 tests/baselines/reference/localTypes1.js      |   3 +-
 tests/baselines/reference/m7Bugs.js           |   3 +-
 .../mergedInterfacesWithInheritedPrivates2.js |   3 +-
 .../mergedInterfacesWithInheritedPrivates3.js |   3 +-
 tests/baselines/reference/moduleAsBaseType.js |   3 +-
 .../moduleImportedForTypeArgumentPosition.js  |   3 +-
 .../moduleWithStatementsOfEveryKind.js        |   3 +-
 .../reference/multipleInheritance.js          |   3 +-
 .../mutuallyRecursiveGenericBaseTypes2.js     |   3 +-
 ...enericClassExtendingGenericClassWithAny.js |   3 +-
 ...cIndexerConstrainsPropertyDeclarations2.js |   3 +-
 .../reference/numericIndexerConstraint3.js    |   3 +-
 .../reference/numericIndexerConstraint4.js    |   3 +-
 .../reference/numericIndexerTyping2.js        |   3 +-
 ...objectCreationOfElementAccessExpression.js |   3 +-
 ...objectTypeHidingMembersOfExtendedObject.js |   3 +-
 ...objectTypesIdentityWithNumericIndexers1.js |   3 +-
 ...objectTypesIdentityWithNumericIndexers2.js |   3 +-
 ...objectTypesIdentityWithNumericIndexers3.js |   3 +-
 .../objectTypesIdentityWithPrivates.js        |   3 +-
 .../objectTypesIdentityWithPrivates2.js       |   3 +-
 .../objectTypesIdentityWithPrivates3.js       |   3 +-
 .../objectTypesIdentityWithStringIndexers.js  |   3 +-
 .../objectTypesIdentityWithStringIndexers2.js |   3 +-
 .../optionalConstructorArgInSuper.js          |   3 +-
 .../reference/optionalParamArgsTest.js        |   3 +-
 .../reference/optionalParamInOverride.js      |   3 +-
 tests/baselines/reference/overload1.js        |   3 +-
 .../overloadOnConstConstraintChecks1.js       |   3 +-
 .../overloadOnConstConstraintChecks2.js       |   3 +-
 .../overloadOnConstConstraintChecks3.js       |   3 +-
 .../overloadOnConstConstraintChecks4.js       |   3 +-
 .../overloadOnConstantsInvalidOverload1.js    |   3 +-
 .../baselines/reference/overloadResolution.js |   3 +-
 .../overloadResolutionClassConstructors.js    |   3 +-
 .../overloadResolutionConstructors.js         |   3 +-
 .../reference/overloadingOnConstants1.js      |   3 +-
 .../reference/overloadingOnConstants2.js      |   3 +-
 .../overridingPrivateStaticMembers.js         |   3 +-
 .../reference/parseErrorInHeritageClause1.js  |   3 +-
 tests/baselines/reference/parser509630.js     |   3 +-
 tests/baselines/reference/parserAstSpans1.js  |   3 +-
 .../reference/parserClassDeclaration1.js      |   3 +-
 .../reference/parserClassDeclaration3.js      |   3 +-
 .../reference/parserClassDeclaration4.js      |   3 +-
 .../reference/parserClassDeclaration5.js      |   3 +-
 .../reference/parserClassDeclaration6.js      |   3 +-
 ...rrorRecovery_ExtendsOrImplementsClause2.js |   3 +-
 ...rrorRecovery_ExtendsOrImplementsClause4.js |   3 +-
 ...rrorRecovery_ExtendsOrImplementsClause5.js |   3 +-
 .../parserGenericsInTypeContexts1.js          |   3 +-
 .../parserGenericsInTypeContexts2.js          |   3 +-
 .../baselines/reference/parserRealSource10.js |   3 +-
 .../baselines/reference/parserRealSource11.js |   3 +-
 tests/baselines/reference/parserharness.js    |   3 +-
 tests/baselines/reference/primitiveMembers.js |   3 +-
 tests/baselines/reference/privacyClass.js     |   3 +-
 .../privacyClassExtendsClauseDeclFile.js      |   6 +-
 tests/baselines/reference/privacyGloClass.js  |   3 +-
 .../reference/privateAccessInSubclass1.js     |   3 +-
 .../privateInstanceMemberAccessibility.js     |   3 +-
 .../privateStaticMemberAccessibility.js       |   3 +-
 .../privateStaticNotAccessibleInClodule2.js   |   3 +-
 .../amd/testGlo.js                            |   3 +-
 .../node/testGlo.js                           |   3 +-
 .../reference/project/prologueEmit/amd/out.js |   3 +-
 .../project/prologueEmit/node/out.js          |   3 +-
 .../amd/m'ain.d.ts                            |   3 -
 .../amd/m'ain.js                              |   3 +-
 .../node/m'ain.d.ts                           |   3 -
 .../node/m'ain.js                             |   3 +-
 .../reference/propertiesAndIndexers.js        |   3 +-
 tests/baselines/reference/propertyAccess.js   |   3 +-
 ...tyAccessOnTypeParameterWithConstraints2.js |   3 +-
 ...tyAccessOnTypeParameterWithConstraints3.js |   3 +-
 ...tyAccessOnTypeParameterWithConstraints5.js |   3 +-
 ...edClassPropertyAccessibleWithinSubclass.js |   3 +-
 ...dClassPropertyAccessibleWithinSubclass2.js |   3 +-
 ...dClassPropertyAccessibleWithinSubclass3.js |   3 +-
 .../protectedInstanceMemberAccessibility.js   |   3 +-
 tests/baselines/reference/protectedMembers.js |   3 +-
 ...icClassPropertyAccessibleWithinSubclass.js |   3 +-
 ...cClassPropertyAccessibleWithinSubclass2.js |   3 +-
 ...solution-does-not-affect-class-heritage.js |   3 +-
 .../reference/recursiveBaseCheck3.js          |   3 +-
 .../reference/recursiveBaseCheck4.js          |   3 +-
 .../reference/recursiveBaseCheck6.js          |   3 +-
 .../recursiveBaseConstructorCreation1.js      |   3 +-
 ...ssInstantiationsWithDefaultConstructors.js |   3 +-
 .../reference/recursiveClassReferenceTest.js  |   3 +-
 .../recursiveClassReferenceTest.js.map        |   2 +-
 .../recursiveClassReferenceTest.sourcemap.txt | 807 +++++++++---------
 .../reference/recursiveComplicatedClasses.js  |   3 +-
 ...sivelySpecializedConstructorDeclaration.js |   3 +-
 ...lassDeclarationWhenInBaseTypeResolution.js |   3 +-
 .../reference/returnInConstructor1.js         |   3 +-
 tests/baselines/reference/returnStatements.js |   3 +-
 ...peCheckExtendedClassInsidePublicMethod2.js |   3 +-
 ...peCheckExtendedClassInsideStaticMethod1.js |   3 +-
 tests/baselines/reference/scopeTests.js       |   3 +-
 .../reference/shadowPrivateMembers.js         |   3 +-
 ...sWithDefaultConstructorAndExtendsClause.js |   3 +-
 ...hDefaultConstructorAndExtendsClause.js.map |   2 +-
 ...tConstructorAndExtendsClause.sourcemap.txt |  75 +-
 .../specializedInheritedConstructors1.js      |   3 +-
 .../specializedOverloadWithRestParameters.js  |   3 +-
 tests/baselines/reference/staticFactory1.js   |   3 +-
 .../baselines/reference/staticInheritance.js  |   3 +-
 .../staticMemberAccessOffDerivedType1.js      |   3 +-
 tests/baselines/reference/staticPropSuper.js  |   3 +-
 .../reference/strictModeInConstructor.js      |   3 +-
 ...trictModeReservedWordInClassDeclaration.js |   3 +-
 ...gIndexerConstrainsPropertyDeclarations2.js |   3 +-
 .../reference/subtypesOfTypeParameter.js      |   3 +-
 .../subtypesOfTypeParameterWithConstraints.js |   3 +-
 ...subtypesOfTypeParameterWithConstraints4.js |   3 +-
 ...OfTypeParameterWithRecursiveConstraints.js |   3 +-
 .../reference/subtypingTransitivity.js        |   3 +-
 .../reference/subtypingWithCallSignatures2.js |   3 +-
 .../reference/subtypingWithCallSignatures3.js |   3 +-
 .../reference/subtypingWithCallSignatures4.js |   3 +-
 .../subtypingWithConstructSignatures2.js      |   3 +-
 .../subtypingWithConstructSignatures3.js      |   3 +-
 .../subtypingWithConstructSignatures4.js      |   3 +-
 .../subtypingWithConstructSignatures5.js      |   3 +-
 .../subtypingWithConstructSignatures6.js      |   3 +-
 .../reference/subtypingWithNumericIndexer.js  |   3 +-
 .../reference/subtypingWithNumericIndexer3.js |   3 +-
 .../reference/subtypingWithNumericIndexer4.js |   3 +-
 .../reference/subtypingWithObjectMembers.js   |   3 +-
 .../reference/subtypingWithObjectMembers4.js  |   3 +-
 ...subtypingWithObjectMembersAccessibility.js |   3 +-
 ...ubtypingWithObjectMembersAccessibility2.js |   3 +-
 .../reference/subtypingWithStringIndexer.js   |   3 +-
 .../reference/subtypingWithStringIndexer3.js  |   3 +-
 .../reference/subtypingWithStringIndexer4.js  |   3 +-
 tests/baselines/reference/super.js            |   3 +-
 tests/baselines/reference/super1.js           |   3 +-
 tests/baselines/reference/super2.js           |   3 +-
 tests/baselines/reference/superAccess.js      |   3 +-
 tests/baselines/reference/superAccess2.js     |   3 +-
 .../reference/superAccessInFatArrow1.js       |   3 +-
 .../reference/superCallArgsMustMatch.js       |   3 +-
 .../reference/superCallAssignResult.js        |   3 +-
 ...allFromClassThatDerivesFromGenericType1.js |   3 +-
 ...allFromClassThatDerivesFromGenericType2.js |   3 +-
 ...eButWithIncorrectNumberOfTypeArguments1.js |   3 +-
 ...sFromGenericTypeButWithNoTypeArguments1.js |   3 +-
 ...ivesNonGenericTypeButWithTypeArguments1.js |   3 +-
 .../reference/superCallInNonStaticMethod.js   |   3 +-
 .../reference/superCallInStaticMethod.js      |   3 +-
 .../reference/superCallOutsideConstructor.js  |   3 +-
 .../superCallParameterContextualTyping1.js    |   3 +-
 .../superCallParameterContextualTyping2.js    |   3 +-
 .../superCallParameterContextualTyping3.js    |   3 +-
 tests/baselines/reference/superCalls.js       |   3 +-
 .../reference/superCallsInConstructor.js      |   3 +-
 tests/baselines/reference/superErrors.js      |   3 +-
 .../baselines/reference/superInCatchBlock1.js |   3 +-
 .../reference/superInConstructorParam1.js     |   3 +-
 tests/baselines/reference/superInLambdas.js   |   3 +-
 tests/baselines/reference/superNewCall1.js    |   3 +-
 .../reference/superPropertyAccess.js          |   3 +-
 .../reference/superPropertyAccess1.js         |   3 +-
 .../reference/superPropertyAccess2.js         |   3 +-
 .../reference/superPropertyAccessNoError.js   |   3 +-
 .../superWithGenericSpecialization.js         |   3 +-
 .../baselines/reference/superWithGenerics.js  |   3 +-
 .../reference/superWithTypeArgument.js        |   3 +-
 .../reference/superWithTypeArgument2.js       |   3 +-
 .../reference/superWithTypeArgument3.js       |   3 +-
 ...side-object-literal-getters-and-setters.js |   3 +-
 tests/baselines/reference/switchStatements.js |   3 +-
 .../reference/targetTypeBaseCalls.js          |   3 +-
 .../reference/thisInInvalidContexts.js        |   3 +-
 .../thisInInvalidContextsExternalModule.js    |   3 +-
 tests/baselines/reference/thisInSuperCall.js  |   3 +-
 tests/baselines/reference/thisInSuperCall1.js |   3 +-
 tests/baselines/reference/thisInSuperCall2.js |   3 +-
 tests/baselines/reference/thisInSuperCall3.js |   3 +-
 tests/baselines/reference/typeAssertions.js   |   3 +-
 .../baselines/reference/typeGuardFunction.js  |   3 +-
 .../reference/typeGuardFunctionErrors.js      |   3 +-
 .../reference/typeGuardFunctionGenerics.js    |   3 +-
 .../reference/typeGuardOfFormInstanceOf.js    |   3 +-
 .../reference/typeGuardOfFormIsType.js        |   3 +-
 tests/baselines/reference/typeMatch2.js       |   3 +-
 tests/baselines/reference/typeOfSuperCall.js  |   3 +-
 .../reference/typeParameterAsBaseClass.js     |   3 +-
 .../reference/typeParameterAsBaseType.js      |   3 +-
 .../reference/typeParameterExtendingUnion1.js |   3 +-
 .../reference/typeParameterExtendingUnion2.js |   3 +-
 .../baselines/reference/typeValueConflict1.js |   3 +-
 .../baselines/reference/typeValueConflict2.js |   3 +-
 tests/baselines/reference/typeofClass2.js     |   3 +-
 .../typesWithSpecializedCallSignatures.js     |   3 +-
 ...typesWithSpecializedConstructSignatures.js |   3 +-
 tests/baselines/reference/undeclaredBase.js   |   3 +-
 .../undefinedIsSubtypeOfEverything.js         |   3 +-
 .../baselines/reference/underscoreMapFirst.js |   3 +-
 .../reference/unionTypeEquivalence.js         |   3 +-
 .../reference/unionTypeFromArrayLiteral.js    |   3 +-
 .../reference/unionTypesAssignability.js      |   3 +-
 tests/baselines/reference/unknownSymbols1.js  |   3 +-
 .../reference/unspecializedConstraints.js     |   3 +-
 ...untypedFunctionCallsWithTypeParameters1.js |   3 +-
 .../reference/validUseOfThisInSuper.js        |   3 +-
 .../reference/varArgsOnConstructorTypes.js    |   3 +-
 528 files changed, 972 insertions(+), 1510 deletions(-)
 delete mode 100644 tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts
 delete mode 100644 tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.d.ts

diff --git a/tests/baselines/reference/ExportClassWithAccessibleTypesInTypeParameterConstraintsClassHeritageListMemberTypeAnnotations.js b/tests/baselines/reference/ExportClassWithAccessibleTypesInTypeParameterConstraintsClassHeritageListMemberTypeAnnotations.js
index ec30d5b4dc..3e48462062 100644
--- a/tests/baselines/reference/ExportClassWithAccessibleTypesInTypeParameterConstraintsClassHeritageListMemberTypeAnnotations.js
+++ b/tests/baselines/reference/ExportClassWithAccessibleTypesInTypeParameterConstraintsClassHeritageListMemberTypeAnnotations.js
@@ -24,8 +24,7 @@ module A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A;
 (function (A) {
diff --git a/tests/baselines/reference/ExportClassWithInaccessibleTypeInTypeParameterConstraint.js b/tests/baselines/reference/ExportClassWithInaccessibleTypeInTypeParameterConstraint.js
index 4d296bf9ea..a1386033e9 100644
--- a/tests/baselines/reference/ExportClassWithInaccessibleTypeInTypeParameterConstraint.js
+++ b/tests/baselines/reference/ExportClassWithInaccessibleTypeInTypeParameterConstraint.js
@@ -28,8 +28,7 @@ module A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A;
 (function (A) {
diff --git a/tests/baselines/reference/accessOverriddenBaseClassMember1.js b/tests/baselines/reference/accessOverriddenBaseClassMember1.js
index f6d3f29f1a..e3a4d0602b 100644
--- a/tests/baselines/reference/accessOverriddenBaseClassMember1.js
+++ b/tests/baselines/reference/accessOverriddenBaseClassMember1.js
@@ -19,8 +19,7 @@ class ColoredPoint extends Point {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Point = (function () {
     function Point(x, y) {
diff --git a/tests/baselines/reference/accessors_spec_section-4.5_inference.js b/tests/baselines/reference/accessors_spec_section-4.5_inference.js
index 8b75e27031..808019448b 100644
--- a/tests/baselines/reference/accessors_spec_section-4.5_inference.js
+++ b/tests/baselines/reference/accessors_spec_section-4.5_inference.js
@@ -28,8 +28,7 @@ class LanguageSpec_section_4_5_inference {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/aliasUsageInAccessorsOfClass.js b/tests/baselines/reference/aliasUsageInAccessorsOfClass.js
index 06c8b55e23..11e02297e4 100644
--- a/tests/baselines/reference/aliasUsageInAccessorsOfClass.js
+++ b/tests/baselines/reference/aliasUsageInAccessorsOfClass.js
@@ -38,8 +38,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsage1_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/aliasUsageInArray.js b/tests/baselines/reference/aliasUsageInArray.js
index e5d44320c7..ba0c954a3c 100644
--- a/tests/baselines/reference/aliasUsageInArray.js
+++ b/tests/baselines/reference/aliasUsageInArray.js
@@ -32,8 +32,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsageInArray_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/aliasUsageInFunctionExpression.js b/tests/baselines/reference/aliasUsageInFunctionExpression.js
index b7b95661ac..702cbe4d53 100644
--- a/tests/baselines/reference/aliasUsageInFunctionExpression.js
+++ b/tests/baselines/reference/aliasUsageInFunctionExpression.js
@@ -31,8 +31,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsageInFunctionExpression_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/aliasUsageInGenericFunction.js b/tests/baselines/reference/aliasUsageInGenericFunction.js
index 856e6ddb43..8706dd592e 100644
--- a/tests/baselines/reference/aliasUsageInGenericFunction.js
+++ b/tests/baselines/reference/aliasUsageInGenericFunction.js
@@ -35,8 +35,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsageInGenericFunction_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/aliasUsageInIndexerOfClass.js b/tests/baselines/reference/aliasUsageInIndexerOfClass.js
index e05f5e4f5c..78ddd2d4a9 100644
--- a/tests/baselines/reference/aliasUsageInIndexerOfClass.js
+++ b/tests/baselines/reference/aliasUsageInIndexerOfClass.js
@@ -37,8 +37,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsageInIndexerOfClass_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/aliasUsageInObjectLiteral.js b/tests/baselines/reference/aliasUsageInObjectLiteral.js
index cc4b8273e8..f38cdf2111 100644
--- a/tests/baselines/reference/aliasUsageInObjectLiteral.js
+++ b/tests/baselines/reference/aliasUsageInObjectLiteral.js
@@ -32,8 +32,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsageInObjectLiteral_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/aliasUsageInOrExpression.js b/tests/baselines/reference/aliasUsageInOrExpression.js
index f382ee2f61..906a2c019d 100644
--- a/tests/baselines/reference/aliasUsageInOrExpression.js
+++ b/tests/baselines/reference/aliasUsageInOrExpression.js
@@ -35,8 +35,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsageInOrExpression_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/aliasUsageInTypeArgumentOfExtendsClause.js b/tests/baselines/reference/aliasUsageInTypeArgumentOfExtendsClause.js
index 39ff58a532..27f85bb5fc 100644
--- a/tests/baselines/reference/aliasUsageInTypeArgumentOfExtendsClause.js
+++ b/tests/baselines/reference/aliasUsageInTypeArgumentOfExtendsClause.js
@@ -35,8 +35,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsageInTypeArgumentOfExtendsClause_backbone");
 var VisualizationModel = (function (_super) {
@@ -51,8 +50,7 @@ exports.VisualizationModel = VisualizationModel;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var moduleA = require("aliasUsageInTypeArgumentOfExtendsClause_moduleA");
 var C = (function () {
diff --git a/tests/baselines/reference/aliasUsageInVarAssignment.js b/tests/baselines/reference/aliasUsageInVarAssignment.js
index 2de34f0056..bfc63868ff 100644
--- a/tests/baselines/reference/aliasUsageInVarAssignment.js
+++ b/tests/baselines/reference/aliasUsageInVarAssignment.js
@@ -31,8 +31,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("aliasUsageInVarAssignment_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/ambiguousOverloadResolution.js b/tests/baselines/reference/ambiguousOverloadResolution.js
index 8c2ceb055c..23c985d2f8 100644
--- a/tests/baselines/reference/ambiguousOverloadResolution.js
+++ b/tests/baselines/reference/ambiguousOverloadResolution.js
@@ -12,8 +12,7 @@ var t: number = f(x, x); // Not an error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/apparentTypeSubtyping.js b/tests/baselines/reference/apparentTypeSubtyping.js
index 087a91fb02..edc0f21323 100644
--- a/tests/baselines/reference/apparentTypeSubtyping.js
+++ b/tests/baselines/reference/apparentTypeSubtyping.js
@@ -27,8 +27,7 @@ class Derived2<U extends String> extends Base2 { // error because of the prototy
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/apparentTypeSupertype.js b/tests/baselines/reference/apparentTypeSupertype.js
index 0b4462bebe..2ab84c8951 100644
--- a/tests/baselines/reference/apparentTypeSupertype.js
+++ b/tests/baselines/reference/apparentTypeSupertype.js
@@ -17,8 +17,7 @@ class Derived<U extends String> extends Base { // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/arrayAssignmentTest1.js b/tests/baselines/reference/arrayAssignmentTest1.js
index 43aad9921b..70177b4cba 100644
--- a/tests/baselines/reference/arrayAssignmentTest1.js
+++ b/tests/baselines/reference/arrayAssignmentTest1.js
@@ -89,8 +89,7 @@ arr_any = i1; // should be an error - is
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1() {
diff --git a/tests/baselines/reference/arrayAssignmentTest2.js b/tests/baselines/reference/arrayAssignmentTest2.js
index 5aeb74114b..61bddd7e8e 100644
--- a/tests/baselines/reference/arrayAssignmentTest2.js
+++ b/tests/baselines/reference/arrayAssignmentTest2.js
@@ -63,8 +63,7 @@ arr_any = i1; // should be an error - is
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1() {
diff --git a/tests/baselines/reference/arrayBestCommonTypes.js b/tests/baselines/reference/arrayBestCommonTypes.js
index 8d2445e273..95dd299ad4 100644
--- a/tests/baselines/reference/arrayBestCommonTypes.js
+++ b/tests/baselines/reference/arrayBestCommonTypes.js
@@ -111,8 +111,7 @@ module NonEmptyTypes {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var EmptyTypes;
 (function (EmptyTypes) {
diff --git a/tests/baselines/reference/arrayLiteralTypeInference.js b/tests/baselines/reference/arrayLiteralTypeInference.js
index dfd662bbf1..fc573aa390 100644
--- a/tests/baselines/reference/arrayLiteralTypeInference.js
+++ b/tests/baselines/reference/arrayLiteralTypeInference.js
@@ -55,8 +55,7 @@ var z3: { id: number }[] =
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Action = (function () {
     function Action() {
diff --git a/tests/baselines/reference/arrayLiterals.js b/tests/baselines/reference/arrayLiterals.js
index cb1d25258f..0f86b7a7f2 100644
--- a/tests/baselines/reference/arrayLiterals.js
+++ b/tests/baselines/reference/arrayLiterals.js
@@ -41,8 +41,7 @@ var context4: Base[] = [new Derived1(), new Derived1()];
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var arr1 = [[], [1], ['']];
 var arr2 = [[null], [1], ['']];
diff --git a/tests/baselines/reference/arrayLiteralsWithRecursiveGenerics.js b/tests/baselines/reference/arrayLiteralsWithRecursiveGenerics.js
index b3c0a0f787..e303415df0 100644
--- a/tests/baselines/reference/arrayLiteralsWithRecursiveGenerics.js
+++ b/tests/baselines/reference/arrayLiteralsWithRecursiveGenerics.js
@@ -29,8 +29,7 @@ var as = [list, myDerivedList]; // List<number>[]
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var List = (function () {
     function List() {
diff --git a/tests/baselines/reference/arrowFunctionContexts.js b/tests/baselines/reference/arrowFunctionContexts.js
index f4a11fb47a..5d862dcec8 100644
--- a/tests/baselines/reference/arrowFunctionContexts.js
+++ b/tests/baselines/reference/arrowFunctionContexts.js
@@ -100,8 +100,7 @@ var asserted2: any;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // Arrow function used in with statement
 with (window) {
diff --git a/tests/baselines/reference/assignmentCompatWithCallSignatures3.js b/tests/baselines/reference/assignmentCompatWithCallSignatures3.js
index 1ad82ca531..6f2eaf4d5c 100644
--- a/tests/baselines/reference/assignmentCompatWithCallSignatures3.js
+++ b/tests/baselines/reference/assignmentCompatWithCallSignatures3.js
@@ -104,8 +104,7 @@ b18 = a18; // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/assignmentCompatWithCallSignatures4.js b/tests/baselines/reference/assignmentCompatWithCallSignatures4.js
index 387395525a..fc6ca05ad3 100644
--- a/tests/baselines/reference/assignmentCompatWithCallSignatures4.js
+++ b/tests/baselines/reference/assignmentCompatWithCallSignatures4.js
@@ -103,8 +103,7 @@ module Errors {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Errors;
 (function (Errors) {
diff --git a/tests/baselines/reference/assignmentCompatWithCallSignatures5.js b/tests/baselines/reference/assignmentCompatWithCallSignatures5.js
index 2e3790cd52..ddf16c23f4 100644
--- a/tests/baselines/reference/assignmentCompatWithCallSignatures5.js
+++ b/tests/baselines/reference/assignmentCompatWithCallSignatures5.js
@@ -70,8 +70,7 @@ b18 = a18; // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/assignmentCompatWithCallSignatures6.js b/tests/baselines/reference/assignmentCompatWithCallSignatures6.js
index a29a607f9e..e57a5ac07a 100644
--- a/tests/baselines/reference/assignmentCompatWithCallSignatures6.js
+++ b/tests/baselines/reference/assignmentCompatWithCallSignatures6.js
@@ -47,8 +47,7 @@ b16 = x.a16;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/assignmentCompatWithConstructSignatures3.js b/tests/baselines/reference/assignmentCompatWithConstructSignatures3.js
index 32176e764e..d02c635c58 100644
--- a/tests/baselines/reference/assignmentCompatWithConstructSignatures3.js
+++ b/tests/baselines/reference/assignmentCompatWithConstructSignatures3.js
@@ -104,8 +104,7 @@ b18 = a18; // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/assignmentCompatWithConstructSignatures4.js b/tests/baselines/reference/assignmentCompatWithConstructSignatures4.js
index 21bace1645..6f9f20333f 100644
--- a/tests/baselines/reference/assignmentCompatWithConstructSignatures4.js
+++ b/tests/baselines/reference/assignmentCompatWithConstructSignatures4.js
@@ -103,8 +103,7 @@ module Errors {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Errors;
 (function (Errors) {
diff --git a/tests/baselines/reference/assignmentCompatWithConstructSignatures5.js b/tests/baselines/reference/assignmentCompatWithConstructSignatures5.js
index 76be317e95..bd4c73e65d 100644
--- a/tests/baselines/reference/assignmentCompatWithConstructSignatures5.js
+++ b/tests/baselines/reference/assignmentCompatWithConstructSignatures5.js
@@ -70,8 +70,7 @@ b18 = a18; // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/assignmentCompatWithConstructSignatures6.js b/tests/baselines/reference/assignmentCompatWithConstructSignatures6.js
index dc1d0dd2de..98477fa152 100644
--- a/tests/baselines/reference/assignmentCompatWithConstructSignatures6.js
+++ b/tests/baselines/reference/assignmentCompatWithConstructSignatures6.js
@@ -47,8 +47,7 @@ b16 = x.a16;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/assignmentCompatWithNumericIndexer.js b/tests/baselines/reference/assignmentCompatWithNumericIndexer.js
index 6044c40b3c..617d136bbb 100644
--- a/tests/baselines/reference/assignmentCompatWithNumericIndexer.js
+++ b/tests/baselines/reference/assignmentCompatWithNumericIndexer.js
@@ -48,8 +48,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/assignmentCompatWithNumericIndexer3.js b/tests/baselines/reference/assignmentCompatWithNumericIndexer3.js
index b3c073ea0b..0c5b0be038 100644
--- a/tests/baselines/reference/assignmentCompatWithNumericIndexer3.js
+++ b/tests/baselines/reference/assignmentCompatWithNumericIndexer3.js
@@ -45,8 +45,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/assignmentCompatWithObjectMembers4.js b/tests/baselines/reference/assignmentCompatWithObjectMembers4.js
index 229525a91f..20279fb1dc 100644
--- a/tests/baselines/reference/assignmentCompatWithObjectMembers4.js
+++ b/tests/baselines/reference/assignmentCompatWithObjectMembers4.js
@@ -96,8 +96,7 @@ module WithBase {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var OnlyDerived;
 (function (OnlyDerived) {
diff --git a/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality.js b/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality.js
index 629f7bf511..6675fab6d6 100644
--- a/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality.js
+++ b/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality.js
@@ -93,8 +93,7 @@ module SourceHasOptional {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality2.js b/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality2.js
index 4ffec4aa7d..b89106eba2 100644
--- a/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality2.js
+++ b/tests/baselines/reference/assignmentCompatWithObjectMembersOptionality2.js
@@ -95,8 +95,7 @@ module SourceHasOptional {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/assignmentCompatWithStringIndexer.js b/tests/baselines/reference/assignmentCompatWithStringIndexer.js
index 99457453af..3391ac5773 100644
--- a/tests/baselines/reference/assignmentCompatWithStringIndexer.js
+++ b/tests/baselines/reference/assignmentCompatWithStringIndexer.js
@@ -58,8 +58,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/assignmentLHSIsValue.js b/tests/baselines/reference/assignmentLHSIsValue.js
index 33054009d8..127f85512a 100644
--- a/tests/baselines/reference/assignmentLHSIsValue.js
+++ b/tests/baselines/reference/assignmentLHSIsValue.js
@@ -74,8 +74,7 @@ foo() = value;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // expected error for all the LHS of assignments
 var value;
diff --git a/tests/baselines/reference/autolift4.js b/tests/baselines/reference/autolift4.js
index 5986ef4a3f..f4bbad50c6 100644
--- a/tests/baselines/reference/autolift4.js
+++ b/tests/baselines/reference/autolift4.js
@@ -27,8 +27,7 @@ class Point3D extends Point {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Point = (function () {
     function Point(x, y) {
diff --git a/tests/baselines/reference/baseCheck.js b/tests/baselines/reference/baseCheck.js
index 4e7db8e6a5..49038f37b1 100644
--- a/tests/baselines/reference/baseCheck.js
+++ b/tests/baselines/reference/baseCheck.js
@@ -33,8 +33,7 @@ function f() {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C(x, y) {
diff --git a/tests/baselines/reference/baseIndexSignatureResolution.js b/tests/baselines/reference/baseIndexSignatureResolution.js
index 85b76221e3..8463ed58a5 100644
--- a/tests/baselines/reference/baseIndexSignatureResolution.js
+++ b/tests/baselines/reference/baseIndexSignatureResolution.js
@@ -28,8 +28,7 @@ var z: Derived = b.foo();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/baseTypeOrderChecking.js b/tests/baselines/reference/baseTypeOrderChecking.js
index 754d90e21e..4c5fe22ea0 100644
--- a/tests/baselines/reference/baseTypeOrderChecking.js
+++ b/tests/baselines/reference/baseTypeOrderChecking.js
@@ -40,8 +40,7 @@ class Class4<T> extends Class3<T>
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var someVariable;
 var Class1 = (function () {
diff --git a/tests/baselines/reference/baseTypeWrappingInstantiationChain.js b/tests/baselines/reference/baseTypeWrappingInstantiationChain.js
index aaa9371033..1de1ebd4bf 100644
--- a/tests/baselines/reference/baseTypeWrappingInstantiationChain.js
+++ b/tests/baselines/reference/baseTypeWrappingInstantiationChain.js
@@ -30,8 +30,7 @@ class Wrapper<T5> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/bases.js b/tests/baselines/reference/bases.js
index 5687e9e0fe..0275c225da 100644
--- a/tests/baselines/reference/bases.js
+++ b/tests/baselines/reference/bases.js
@@ -24,8 +24,7 @@ new C().y;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B = (function () {
     function B() {
diff --git a/tests/baselines/reference/bestCommonTypeOfConditionalExpressions.js b/tests/baselines/reference/bestCommonTypeOfConditionalExpressions.js
index e56e530ad6..abd2cc5e87 100644
--- a/tests/baselines/reference/bestCommonTypeOfConditionalExpressions.js
+++ b/tests/baselines/reference/bestCommonTypeOfConditionalExpressions.js
@@ -32,8 +32,7 @@ function foo5<T, U>(t: T, u: U): Object {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a;
 var b;
diff --git a/tests/baselines/reference/bestCommonTypeOfConditionalExpressions2.js b/tests/baselines/reference/bestCommonTypeOfConditionalExpressions2.js
index fb3c15a8fb..e0e7bc3f32 100644
--- a/tests/baselines/reference/bestCommonTypeOfConditionalExpressions2.js
+++ b/tests/baselines/reference/bestCommonTypeOfConditionalExpressions2.js
@@ -30,8 +30,7 @@ function foo3<T extends U, U extends V, V>(t: T, u: U) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/bestCommonTypeOfTuple2.js b/tests/baselines/reference/bestCommonTypeOfTuple2.js
index 5642df5570..ed0b0ecb32 100644
--- a/tests/baselines/reference/bestCommonTypeOfTuple2.js
+++ b/tests/baselines/reference/bestCommonTypeOfTuple2.js
@@ -26,8 +26,7 @@ var e51 = t5[2]; // {}
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance2.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance2.js
index 685e33acb6..e43c22fab7 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance2.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance2.js
@@ -74,8 +74,7 @@ interface I extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance3.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance3.js
index 135c0c056a..6105ddf23f 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance3.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance3.js
@@ -119,8 +119,7 @@ module Errors {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Errors;
 (function (Errors) {
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance4.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance4.js
index c578a49ee5..aee3af6f74 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance4.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance4.js
@@ -54,8 +54,7 @@ interface I extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance5.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance5.js
index 74987308ef..c72a77e402 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance5.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance5.js
@@ -54,8 +54,7 @@ interface I extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/callSignatureAssignabilityInInheritance6.js b/tests/baselines/reference/callSignatureAssignabilityInInheritance6.js
index aa2e9787bd..e22bb1189e 100644
--- a/tests/baselines/reference/callSignatureAssignabilityInInheritance6.js
+++ b/tests/baselines/reference/callSignatureAssignabilityInInheritance6.js
@@ -57,8 +57,7 @@ interface I9<T> extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/callWithSpread.js b/tests/baselines/reference/callWithSpread.js
index d21b4879da..50840abfbb 100644
--- a/tests/baselines/reference/callWithSpread.js
+++ b/tests/baselines/reference/callWithSpread.js
@@ -54,8 +54,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function foo(x, y) {
     var z = [];
diff --git a/tests/baselines/reference/captureThisInSuperCall.js b/tests/baselines/reference/captureThisInSuperCall.js
index 27c80e2991..611ad93f53 100644
--- a/tests/baselines/reference/captureThisInSuperCall.js
+++ b/tests/baselines/reference/captureThisInSuperCall.js
@@ -12,8 +12,7 @@ class B extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(p) {
diff --git a/tests/baselines/reference/castingTuple.js b/tests/baselines/reference/castingTuple.js
index 8b1005d448..0102d1310a 100644
--- a/tests/baselines/reference/castingTuple.js
+++ b/tests/baselines/reference/castingTuple.js
@@ -36,8 +36,7 @@ t4[2] = 10;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/chainedAssignment3.js b/tests/baselines/reference/chainedAssignment3.js
index 022668ba7c..04c328031c 100644
--- a/tests/baselines/reference/chainedAssignment3.js
+++ b/tests/baselines/reference/chainedAssignment3.js
@@ -26,8 +26,7 @@ a = b = new A();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js b/tests/baselines/reference/chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js
index 494f0bc1b5..e7e1a3a871 100644
--- a/tests/baselines/reference/chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js
+++ b/tests/baselines/reference/chainedCallsWithTypeParameterConstrainedToOtherTypeParameter.js
@@ -23,8 +23,7 @@ class C extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Chain = (function () {
     function Chain(value) {
diff --git a/tests/baselines/reference/checkForObjectTooStrict.js b/tests/baselines/reference/checkForObjectTooStrict.js
index bcdde6b3be..d8f40a3f1d 100644
--- a/tests/baselines/reference/checkForObjectTooStrict.js
+++ b/tests/baselines/reference/checkForObjectTooStrict.js
@@ -35,8 +35,7 @@ class Baz extends Object {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo;
 (function (Foo) {
diff --git a/tests/baselines/reference/circularImportAlias.js b/tests/baselines/reference/circularImportAlias.js
index 1a50a46221..8b908a97ee 100644
--- a/tests/baselines/reference/circularImportAlias.js
+++ b/tests/baselines/reference/circularImportAlias.js
@@ -24,8 +24,7 @@ var c = new B.a.C();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B;
 (function (B) {
diff --git a/tests/baselines/reference/classConstructorParametersAccessibility.js b/tests/baselines/reference/classConstructorParametersAccessibility.js
index 5d715556ec..a5538b66ec 100644
--- a/tests/baselines/reference/classConstructorParametersAccessibility.js
+++ b/tests/baselines/reference/classConstructorParametersAccessibility.js
@@ -30,8 +30,7 @@ class Derived extends C3 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1(x) {
diff --git a/tests/baselines/reference/classConstructorParametersAccessibility2.js b/tests/baselines/reference/classConstructorParametersAccessibility2.js
index 1d273e119e..581746a180 100644
--- a/tests/baselines/reference/classConstructorParametersAccessibility2.js
+++ b/tests/baselines/reference/classConstructorParametersAccessibility2.js
@@ -30,8 +30,7 @@ class Derived extends C3 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1(x) {
diff --git a/tests/baselines/reference/classConstructorParametersAccessibility3.js b/tests/baselines/reference/classConstructorParametersAccessibility3.js
index 43823bbb4d..d98b094ccd 100644
--- a/tests/baselines/reference/classConstructorParametersAccessibility3.js
+++ b/tests/baselines/reference/classConstructorParametersAccessibility3.js
@@ -17,8 +17,7 @@ d.p;  // public, OK
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(p) {
diff --git a/tests/baselines/reference/classDeclarationMergedInModuleWithContinuation.js b/tests/baselines/reference/classDeclarationMergedInModuleWithContinuation.js
index 7299b04720..a8d6fcd88e 100644
--- a/tests/baselines/reference/classDeclarationMergedInModuleWithContinuation.js
+++ b/tests/baselines/reference/classDeclarationMergedInModuleWithContinuation.js
@@ -15,8 +15,7 @@ module M {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/classDoesNotDependOnBaseTypes.js b/tests/baselines/reference/classDoesNotDependOnBaseTypes.js
index 5247458231..8515e1d98e 100644
--- a/tests/baselines/reference/classDoesNotDependOnBaseTypes.js
+++ b/tests/baselines/reference/classDoesNotDependOnBaseTypes.js
@@ -16,8 +16,7 @@ class StringTreeCollection extends StringTreeCollectionBase { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x;
 if (typeof x !== "string") {
diff --git a/tests/baselines/reference/classExtendingClass.js b/tests/baselines/reference/classExtendingClass.js
index b8e079e8ec..6168cb3418 100644
--- a/tests/baselines/reference/classExtendingClass.js
+++ b/tests/baselines/reference/classExtendingClass.js
@@ -35,8 +35,7 @@ var r8 = D2.other(1);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/classExtendingPrimitive.js b/tests/baselines/reference/classExtendingPrimitive.js
index b099ce763e..cafa4eebcd 100644
--- a/tests/baselines/reference/classExtendingPrimitive.js
+++ b/tests/baselines/reference/classExtendingPrimitive.js
@@ -19,8 +19,7 @@ class C8 extends E { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/classExtendingPrimitive2.js b/tests/baselines/reference/classExtendingPrimitive2.js
index 3dcff0b44b..4661ab961c 100644
--- a/tests/baselines/reference/classExtendingPrimitive2.js
+++ b/tests/baselines/reference/classExtendingPrimitive2.js
@@ -9,8 +9,7 @@ class C5a extends null { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C4a = (function () {
     function C4a() {
diff --git a/tests/baselines/reference/classExtendingQualifiedName.js b/tests/baselines/reference/classExtendingQualifiedName.js
index 0289797d1e..44a4fbe2bd 100644
--- a/tests/baselines/reference/classExtendingQualifiedName.js
+++ b/tests/baselines/reference/classExtendingQualifiedName.js
@@ -11,8 +11,7 @@ module M {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/classExtendingQualifiedName2.js b/tests/baselines/reference/classExtendingQualifiedName2.js
index 76065ccc57..afd432180d 100644
--- a/tests/baselines/reference/classExtendingQualifiedName2.js
+++ b/tests/baselines/reference/classExtendingQualifiedName2.js
@@ -11,8 +11,7 @@ module M {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/classExtendsClauseClassMergedWithModuleNotReferingConstructor.js b/tests/baselines/reference/classExtendsClauseClassMergedWithModuleNotReferingConstructor.js
index 726f918f4e..fe8dc79b86 100644
--- a/tests/baselines/reference/classExtendsClauseClassMergedWithModuleNotReferingConstructor.js
+++ b/tests/baselines/reference/classExtendsClauseClassMergedWithModuleNotReferingConstructor.js
@@ -17,8 +17,7 @@ module Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classExtendsClauseClassNotReferringConstructor.js b/tests/baselines/reference/classExtendsClauseClassNotReferringConstructor.js
index 8dc3410a17..94c5067915 100644
--- a/tests/baselines/reference/classExtendsClauseClassNotReferringConstructor.js
+++ b/tests/baselines/reference/classExtendsClauseClassNotReferringConstructor.js
@@ -10,8 +10,7 @@ module Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classExtendsEveryObjectType.js b/tests/baselines/reference/classExtendsEveryObjectType.js
index afbb4dab71..92414c7e6c 100644
--- a/tests/baselines/reference/classExtendsEveryObjectType.js
+++ b/tests/baselines/reference/classExtendsEveryObjectType.js
@@ -20,8 +20,7 @@ class C6 extends []{ } // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/classExtendsEveryObjectType2.js b/tests/baselines/reference/classExtendsEveryObjectType2.js
index c41943072d..2735032f3c 100644
--- a/tests/baselines/reference/classExtendsEveryObjectType2.js
+++ b/tests/baselines/reference/classExtendsEveryObjectType2.js
@@ -7,8 +7,7 @@ class C6 extends []{ } // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C2 = (function (_super) {
     __extends(C2, _super);
diff --git a/tests/baselines/reference/classExtendsInterface.js b/tests/baselines/reference/classExtendsInterface.js
index a3e596299f..9b78cde35e 100644
--- a/tests/baselines/reference/classExtendsInterface.js
+++ b/tests/baselines/reference/classExtendsInterface.js
@@ -12,8 +12,7 @@ class B2<T> implements Comparable2<T> {}
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function (_super) {
     __extends(A, _super);
diff --git a/tests/baselines/reference/classExtendsItself.js b/tests/baselines/reference/classExtendsItself.js
index 79a4226731..c370e797a5 100644
--- a/tests/baselines/reference/classExtendsItself.js
+++ b/tests/baselines/reference/classExtendsItself.js
@@ -9,8 +9,7 @@ class E<T> extends E<string> { } // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/classExtendsItselfIndirectly.js b/tests/baselines/reference/classExtendsItselfIndirectly.js
index eee52b877e..65cd72ce3c 100644
--- a/tests/baselines/reference/classExtendsItselfIndirectly.js
+++ b/tests/baselines/reference/classExtendsItselfIndirectly.js
@@ -15,8 +15,7 @@ class E2<T> extends D2<T> { baz: T; }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/classExtendsItselfIndirectly2.js b/tests/baselines/reference/classExtendsItselfIndirectly2.js
index 02201425cb..c0b46e6cbb 100644
--- a/tests/baselines/reference/classExtendsItselfIndirectly2.js
+++ b/tests/baselines/reference/classExtendsItselfIndirectly2.js
@@ -26,8 +26,7 @@ module O {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/classExtendsItselfIndirectly3.js b/tests/baselines/reference/classExtendsItselfIndirectly3.js
index bff6dd92bc..9241403a7c 100644
--- a/tests/baselines/reference/classExtendsItselfIndirectly3.js
+++ b/tests/baselines/reference/classExtendsItselfIndirectly3.js
@@ -22,8 +22,7 @@ class E2<T> extends D2<T> { baz: T; }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
@@ -36,8 +35,7 @@ var C = (function (_super) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var D = (function (_super) {
     __extends(D, _super);
@@ -50,8 +48,7 @@ var D = (function (_super) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var E = (function (_super) {
     __extends(E, _super);
@@ -64,8 +61,7 @@ var E = (function (_super) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C2 = (function (_super) {
     __extends(C2, _super);
@@ -78,8 +74,7 @@ var C2 = (function (_super) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var D2 = (function (_super) {
     __extends(D2, _super);
@@ -92,8 +87,7 @@ var D2 = (function (_super) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var E2 = (function (_super) {
     __extends(E2, _super);
diff --git a/tests/baselines/reference/classExtendsMultipleBaseClasses.js b/tests/baselines/reference/classExtendsMultipleBaseClasses.js
index 7027e85450..d1ffee3041 100644
--- a/tests/baselines/reference/classExtendsMultipleBaseClasses.js
+++ b/tests/baselines/reference/classExtendsMultipleBaseClasses.js
@@ -7,8 +7,7 @@ class C extends A,B { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classExtendsShadowedConstructorFunction.js b/tests/baselines/reference/classExtendsShadowedConstructorFunction.js
index 48f2e79113..164ffdc849 100644
--- a/tests/baselines/reference/classExtendsShadowedConstructorFunction.js
+++ b/tests/baselines/reference/classExtendsShadowedConstructorFunction.js
@@ -12,8 +12,7 @@ module M {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/classExtendsValidConstructorFunction.js b/tests/baselines/reference/classExtendsValidConstructorFunction.js
index 411bd3c2fb..448db68db9 100644
--- a/tests/baselines/reference/classExtendsValidConstructorFunction.js
+++ b/tests/baselines/reference/classExtendsValidConstructorFunction.js
@@ -9,8 +9,7 @@ class C extends foo { } // error, cannot extend it though
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function foo() { }
 var x = new foo(); // can be used as a constructor function
diff --git a/tests/baselines/reference/classHeritageWithTrailingSeparator.js b/tests/baselines/reference/classHeritageWithTrailingSeparator.js
index 6d33f79a4d..2d5b12d520 100644
--- a/tests/baselines/reference/classHeritageWithTrailingSeparator.js
+++ b/tests/baselines/reference/classHeritageWithTrailingSeparator.js
@@ -7,8 +7,7 @@ class D extends C, {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/classImplementsClass2.js b/tests/baselines/reference/classImplementsClass2.js
index 49b73bfdb1..490d2706b4 100644
--- a/tests/baselines/reference/classImplementsClass2.js
+++ b/tests/baselines/reference/classImplementsClass2.js
@@ -17,8 +17,7 @@ c2 = c;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classImplementsClass3.js b/tests/baselines/reference/classImplementsClass3.js
index f8773b435b..00cb49e2da 100644
--- a/tests/baselines/reference/classImplementsClass3.js
+++ b/tests/baselines/reference/classImplementsClass3.js
@@ -18,8 +18,7 @@ c2 = c;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classImplementsClass4.js b/tests/baselines/reference/classImplementsClass4.js
index cf442b0ad2..0d7508b723 100644
--- a/tests/baselines/reference/classImplementsClass4.js
+++ b/tests/baselines/reference/classImplementsClass4.js
@@ -20,8 +20,7 @@ c2 = c;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classImplementsClass5.js b/tests/baselines/reference/classImplementsClass5.js
index a648f6bd63..caacb7b304 100644
--- a/tests/baselines/reference/classImplementsClass5.js
+++ b/tests/baselines/reference/classImplementsClass5.js
@@ -21,8 +21,7 @@ c2 = c;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classImplementsClass6.js b/tests/baselines/reference/classImplementsClass6.js
index af6f0844d2..2e8d765be8 100644
--- a/tests/baselines/reference/classImplementsClass6.js
+++ b/tests/baselines/reference/classImplementsClass6.js
@@ -25,8 +25,7 @@ c2.bar(); // should error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classIndexer3.js b/tests/baselines/reference/classIndexer3.js
index 9f630b9630..e962c7295f 100644
--- a/tests/baselines/reference/classIndexer3.js
+++ b/tests/baselines/reference/classIndexer3.js
@@ -14,8 +14,7 @@ class D123 extends C123 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C123 = (function () {
     function C123() {
diff --git a/tests/baselines/reference/classInheritence.js b/tests/baselines/reference/classInheritence.js
index 374248c3a2..1e463dd195 100644
--- a/tests/baselines/reference/classInheritence.js
+++ b/tests/baselines/reference/classInheritence.js
@@ -6,8 +6,7 @@ class A extends A { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B = (function (_super) {
     __extends(B, _super);
diff --git a/tests/baselines/reference/classIsSubtypeOfBaseType.js b/tests/baselines/reference/classIsSubtypeOfBaseType.js
index a33bf5499b..a92cfb430b 100644
--- a/tests/baselines/reference/classIsSubtypeOfBaseType.js
+++ b/tests/baselines/reference/classIsSubtypeOfBaseType.js
@@ -19,8 +19,7 @@ class Derived2 extends Base<{ bar: string; }> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/classOrder2.js b/tests/baselines/reference/classOrder2.js
index 8eed39bdde..fd3fee2e03 100644
--- a/tests/baselines/reference/classOrder2.js
+++ b/tests/baselines/reference/classOrder2.js
@@ -23,8 +23,7 @@ a.foo();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function (_super) {
     __extends(A, _super);
diff --git a/tests/baselines/reference/classOrderBug.js b/tests/baselines/reference/classOrderBug.js
index ae50152d60..bc3f0e739c 100644
--- a/tests/baselines/reference/classOrderBug.js
+++ b/tests/baselines/reference/classOrderBug.js
@@ -19,8 +19,7 @@ class foo extends baz {}
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var bar = (function () {
     function bar() {
diff --git a/tests/baselines/reference/classSideInheritance1.js b/tests/baselines/reference/classSideInheritance1.js
index 66cbc0c25c..6d217149b8 100644
--- a/tests/baselines/reference/classSideInheritance1.js
+++ b/tests/baselines/reference/classSideInheritance1.js
@@ -19,8 +19,7 @@ C2.bar(); // valid
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/classSideInheritance2.js b/tests/baselines/reference/classSideInheritance2.js
index e09301fe85..fb6f0d8cbb 100644
--- a/tests/baselines/reference/classSideInheritance2.js
+++ b/tests/baselines/reference/classSideInheritance2.js
@@ -24,8 +24,7 @@ class TextBase implements IText {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var SubText = (function (_super) {
     __extends(SubText, _super);
diff --git a/tests/baselines/reference/classSideInheritance3.js b/tests/baselines/reference/classSideInheritance3.js
index a69b6ff034..0891a7c9e7 100644
--- a/tests/baselines/reference/classSideInheritance3.js
+++ b/tests/baselines/reference/classSideInheritance3.js
@@ -22,8 +22,7 @@ var r3: typeof A = C; // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(x) {
diff --git a/tests/baselines/reference/classUpdateTests.js b/tests/baselines/reference/classUpdateTests.js
index 90149d88d9..95db2680a1 100644
--- a/tests/baselines/reference/classUpdateTests.js
+++ b/tests/baselines/reference/classUpdateTests.js
@@ -117,8 +117,7 @@ class R {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 //
 // test codegen for instance properties
diff --git a/tests/baselines/reference/classWithBaseClassButNoConstructor.js b/tests/baselines/reference/classWithBaseClassButNoConstructor.js
index f1a10b317a..44e5d39c37 100644
--- a/tests/baselines/reference/classWithBaseClassButNoConstructor.js
+++ b/tests/baselines/reference/classWithBaseClassButNoConstructor.js
@@ -44,8 +44,7 @@ var d6 = new D(1); // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(x) {
diff --git a/tests/baselines/reference/classWithConstructors.js b/tests/baselines/reference/classWithConstructors.js
index 467738e096..a36db6ee74 100644
--- a/tests/baselines/reference/classWithConstructors.js
+++ b/tests/baselines/reference/classWithConstructors.js
@@ -53,8 +53,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var NonGeneric;
 (function (NonGeneric) {
diff --git a/tests/baselines/reference/classWithProtectedProperty.js b/tests/baselines/reference/classWithProtectedProperty.js
index 7d86e1c722..ec8a203d20 100644
--- a/tests/baselines/reference/classWithProtectedProperty.js
+++ b/tests/baselines/reference/classWithProtectedProperty.js
@@ -32,8 +32,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/classWithStaticMembers.js b/tests/baselines/reference/classWithStaticMembers.js
index edad6c22c7..34928c37ab 100644
--- a/tests/baselines/reference/classWithStaticMembers.js
+++ b/tests/baselines/reference/classWithStaticMembers.js
@@ -23,8 +23,7 @@ var r3 = r.foo;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C(a, b) {
diff --git a/tests/baselines/reference/classdecl.js b/tests/baselines/reference/classdecl.js
index 127e0e9f32..2af85da5b5 100644
--- a/tests/baselines/reference/classdecl.js
+++ b/tests/baselines/reference/classdecl.js
@@ -97,8 +97,7 @@ class e {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a(ns) {
diff --git a/tests/baselines/reference/clodulesDerivedClasses.js b/tests/baselines/reference/clodulesDerivedClasses.js
index c37b9f0e96..652b3f7bac 100644
--- a/tests/baselines/reference/clodulesDerivedClasses.js
+++ b/tests/baselines/reference/clodulesDerivedClasses.js
@@ -26,8 +26,7 @@ module Path.Utils {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Shape = (function () {
     function Shape() {
diff --git a/tests/baselines/reference/collisionSuperAndLocalFunctionInAccessors.js b/tests/baselines/reference/collisionSuperAndLocalFunctionInAccessors.js
index a58f4aa9f9..731f3d4f06 100644
--- a/tests/baselines/reference/collisionSuperAndLocalFunctionInAccessors.js
+++ b/tests/baselines/reference/collisionSuperAndLocalFunctionInAccessors.js
@@ -43,8 +43,7 @@ class c extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function _super() {
 }
diff --git a/tests/baselines/reference/collisionSuperAndLocalFunctionInConstructor.js b/tests/baselines/reference/collisionSuperAndLocalFunctionInConstructor.js
index b89a8753ac..06acaa0e02 100644
--- a/tests/baselines/reference/collisionSuperAndLocalFunctionInConstructor.js
+++ b/tests/baselines/reference/collisionSuperAndLocalFunctionInConstructor.js
@@ -28,8 +28,7 @@ class c extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function _super() {
 }
diff --git a/tests/baselines/reference/collisionSuperAndLocalFunctionInMethod.js b/tests/baselines/reference/collisionSuperAndLocalFunctionInMethod.js
index efa9c1d9f0..6702ba8ac3 100644
--- a/tests/baselines/reference/collisionSuperAndLocalFunctionInMethod.js
+++ b/tests/baselines/reference/collisionSuperAndLocalFunctionInMethod.js
@@ -32,8 +32,7 @@ class c extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function _super() {
 }
diff --git a/tests/baselines/reference/collisionSuperAndLocalFunctionInProperty.js b/tests/baselines/reference/collisionSuperAndLocalFunctionInProperty.js
index 228b7243d4..8d13eed617 100644
--- a/tests/baselines/reference/collisionSuperAndLocalFunctionInProperty.js
+++ b/tests/baselines/reference/collisionSuperAndLocalFunctionInProperty.js
@@ -22,8 +22,7 @@ class b extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function _super() {
 }
diff --git a/tests/baselines/reference/collisionSuperAndLocalVarInAccessors.js b/tests/baselines/reference/collisionSuperAndLocalVarInAccessors.js
index d2392f4df3..1268572779 100644
--- a/tests/baselines/reference/collisionSuperAndLocalVarInAccessors.js
+++ b/tests/baselines/reference/collisionSuperAndLocalVarInAccessors.js
@@ -36,8 +36,7 @@ class c extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var _super = 10; // No Error
 var Foo = (function () {
diff --git a/tests/baselines/reference/collisionSuperAndLocalVarInConstructor.js b/tests/baselines/reference/collisionSuperAndLocalVarInConstructor.js
index dc3210c1f8..6f54349289 100644
--- a/tests/baselines/reference/collisionSuperAndLocalVarInConstructor.js
+++ b/tests/baselines/reference/collisionSuperAndLocalVarInConstructor.js
@@ -24,8 +24,7 @@ class c extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var _super = 10; // No Error
 var Foo = (function () {
diff --git a/tests/baselines/reference/collisionSuperAndLocalVarInMethod.js b/tests/baselines/reference/collisionSuperAndLocalVarInMethod.js
index 7a6ee0c45c..373ee27001 100644
--- a/tests/baselines/reference/collisionSuperAndLocalVarInMethod.js
+++ b/tests/baselines/reference/collisionSuperAndLocalVarInMethod.js
@@ -22,8 +22,7 @@ class c extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var _super = 10; // No Error
 var Foo = (function () {
diff --git a/tests/baselines/reference/collisionSuperAndLocalVarInProperty.js b/tests/baselines/reference/collisionSuperAndLocalVarInProperty.js
index f678c7cf6c..7ba9b40785 100644
--- a/tests/baselines/reference/collisionSuperAndLocalVarInProperty.js
+++ b/tests/baselines/reference/collisionSuperAndLocalVarInProperty.js
@@ -21,8 +21,7 @@ class b extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var _super = 10; // No Error
 var Foo = (function () {
diff --git a/tests/baselines/reference/collisionSuperAndNameResolution.js b/tests/baselines/reference/collisionSuperAndNameResolution.js
index 540a2b659d..5cddcc0184 100644
--- a/tests/baselines/reference/collisionSuperAndNameResolution.js
+++ b/tests/baselines/reference/collisionSuperAndNameResolution.js
@@ -15,8 +15,7 @@ class Foo extends base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var console;
 var _super = 10; // No error
diff --git a/tests/baselines/reference/collisionSuperAndParameter.js b/tests/baselines/reference/collisionSuperAndParameter.js
index ac8947e00d..965887d6d1 100644
--- a/tests/baselines/reference/collisionSuperAndParameter.js
+++ b/tests/baselines/reference/collisionSuperAndParameter.js
@@ -66,8 +66,7 @@ class Foo4 extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/collisionSuperAndParameter1.js b/tests/baselines/reference/collisionSuperAndParameter1.js
index b072667396..f6d1f23947 100644
--- a/tests/baselines/reference/collisionSuperAndParameter1.js
+++ b/tests/baselines/reference/collisionSuperAndParameter1.js
@@ -13,8 +13,7 @@ class Foo2 extends Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/collisionSuperAndPropertyNameAsConstuctorParameter.js b/tests/baselines/reference/collisionSuperAndPropertyNameAsConstuctorParameter.js
index e96ae7d892..f54bbef28a 100644
--- a/tests/baselines/reference/collisionSuperAndPropertyNameAsConstuctorParameter.js
+++ b/tests/baselines/reference/collisionSuperAndPropertyNameAsConstuctorParameter.js
@@ -34,8 +34,7 @@ class b4 extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/collisionThisExpressionAndLocalVarWithSuperExperssion.js b/tests/baselines/reference/collisionThisExpressionAndLocalVarWithSuperExperssion.js
index dbf36111df..eb2ddd825f 100644
--- a/tests/baselines/reference/collisionThisExpressionAndLocalVarWithSuperExperssion.js
+++ b/tests/baselines/reference/collisionThisExpressionAndLocalVarWithSuperExperssion.js
@@ -22,8 +22,7 @@ class b2 extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/commentsInheritance.js b/tests/baselines/reference/commentsInheritance.js
index 4fe5a30cb8..3372643618 100644
--- a/tests/baselines/reference/commentsInheritance.js
+++ b/tests/baselines/reference/commentsInheritance.js
@@ -155,8 +155,7 @@ i2_i = i3_i;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var c1 = (function () {
     function c1() {
diff --git a/tests/baselines/reference/comparisonOperatorWithIdenticalObjects.js b/tests/baselines/reference/comparisonOperatorWithIdenticalObjects.js
index aebb486a1b..d59ec76468 100644
--- a/tests/baselines/reference/comparisonOperatorWithIdenticalObjects.js
+++ b/tests/baselines/reference/comparisonOperatorWithIdenticalObjects.js
@@ -198,8 +198,7 @@ var r8b7 = b6 !== a6;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A1 = (function () {
     function A1() {
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnCallSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnCallSignature.js
index 3d7e96be63..4bbc7675a3 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnCallSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnCallSignature.js
@@ -172,8 +172,7 @@ var r8b7 = b7 !== a7;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnConstructorSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnConstructorSignature.js
index 097246f183..397c7e9d8e 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnConstructorSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnConstructorSignature.js
@@ -172,8 +172,7 @@ var r8b7 = b7 !== a7;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnIndexSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnIndexSignature.js
index 6bb3cddc8a..9f3c037538 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnIndexSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnIndexSignature.js
@@ -115,8 +115,7 @@ var r8b4 = b4 !== a4;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedCallSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedCallSignature.js
index dee8fb5ed5..68ebcb9d59 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedCallSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedCallSignature.js
@@ -153,8 +153,7 @@ var r8b6 = b6 !== a6;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedConstructorSignature.js b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedConstructorSignature.js
index bc7db12ebf..60177f0ea2 100644
--- a/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedConstructorSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithNoRelationshipObjectsOnInstantiatedConstructorSignature.js
@@ -153,8 +153,7 @@ var r8b6 = b6 !== a6;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnCallSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnCallSignature.js
index a35ece1b61..27d1b68c85 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnCallSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnCallSignature.js
@@ -263,8 +263,7 @@ var r8b11 = b11 !== a11;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnConstructorSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnConstructorSignature.js
index 8ade79daa2..5a98e12b00 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnConstructorSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnConstructorSignature.js
@@ -225,8 +225,7 @@ var r8b9 = b9 !== a9;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnIndexSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnIndexSignature.js
index 080c7990c0..24069615e0 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnIndexSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnIndexSignature.js
@@ -111,8 +111,7 @@ var r8b1 = b4 !== a4;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedCallSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedCallSignature.js
index f01b18496d..f0dac057ca 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedCallSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedCallSignature.js
@@ -168,8 +168,7 @@ var r8b6 = b6 !== a6;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedConstructorSignature.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedConstructorSignature.js
index bd4525e5c7..eaf1aca728 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedConstructorSignature.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnInstantiatedConstructorSignature.js
@@ -168,8 +168,7 @@ var r8b6 = b6 !== a6;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnProperty.js b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnProperty.js
index cbd31f56b3..822d4b7520 100644
--- a/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnProperty.js
+++ b/tests/baselines/reference/comparisonOperatorWithSubtypeObjectOnProperty.js
@@ -82,8 +82,7 @@ var rh4 = b2 !== a2;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/complexClassRelationships.js b/tests/baselines/reference/complexClassRelationships.js
index 2d750b77f7..ca2b31a805 100644
--- a/tests/baselines/reference/complexClassRelationships.js
+++ b/tests/baselines/reference/complexClassRelationships.js
@@ -51,8 +51,7 @@ class FooBase {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // There should be no errors in this file
 var Derived = (function (_super) {
diff --git a/tests/baselines/reference/complicatedGenericRecursiveBaseClassReference.js b/tests/baselines/reference/complicatedGenericRecursiveBaseClassReference.js
index 920172b206..71c1cee164 100644
--- a/tests/baselines/reference/complicatedGenericRecursiveBaseClassReference.js
+++ b/tests/baselines/reference/complicatedGenericRecursiveBaseClassReference.js
@@ -9,8 +9,7 @@ class S18<B, A, C> extends S18<A[], { S19: A; (): A }[], C[]>
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var S18 = (function (_super) {
     __extends(S18, _super);
diff --git a/tests/baselines/reference/compoundAssignmentLHSIsValue.js b/tests/baselines/reference/compoundAssignmentLHSIsValue.js
index 4c5c050dc8..833c1e1ea7 100644
--- a/tests/baselines/reference/compoundAssignmentLHSIsValue.js
+++ b/tests/baselines/reference/compoundAssignmentLHSIsValue.js
@@ -126,8 +126,7 @@ foo() += value;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // expected error for all the LHS of compound assignments (arithmetic and addition)
 var value;
diff --git a/tests/baselines/reference/computedPropertyNames24_ES5.js b/tests/baselines/reference/computedPropertyNames24_ES5.js
index e433383eb5..5a4b79cf44 100644
--- a/tests/baselines/reference/computedPropertyNames24_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames24_ES5.js
@@ -12,8 +12,7 @@ class C extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/computedPropertyNames25_ES5.js b/tests/baselines/reference/computedPropertyNames25_ES5.js
index eca2485ab7..832fad174d 100644
--- a/tests/baselines/reference/computedPropertyNames25_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames25_ES5.js
@@ -17,8 +17,7 @@ class C extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/computedPropertyNames26_ES5.js b/tests/baselines/reference/computedPropertyNames26_ES5.js
index 0e3b6c126b..09a9541948 100644
--- a/tests/baselines/reference/computedPropertyNames26_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames26_ES5.js
@@ -14,8 +14,7 @@ class C extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/computedPropertyNames27_ES5.js b/tests/baselines/reference/computedPropertyNames27_ES5.js
index 12f02fbefa..53e2c2988c 100644
--- a/tests/baselines/reference/computedPropertyNames27_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames27_ES5.js
@@ -9,8 +9,7 @@ class C extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/computedPropertyNames28_ES5.js b/tests/baselines/reference/computedPropertyNames28_ES5.js
index b2be5f120a..be79f22c2d 100644
--- a/tests/baselines/reference/computedPropertyNames28_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames28_ES5.js
@@ -14,8 +14,7 @@ class C extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/computedPropertyNames30_ES5.js b/tests/baselines/reference/computedPropertyNames30_ES5.js
index 6bbca3da05..de60b5daf5 100644
--- a/tests/baselines/reference/computedPropertyNames30_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames30_ES5.js
@@ -19,8 +19,7 @@ class C extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/computedPropertyNames31_ES5.js b/tests/baselines/reference/computedPropertyNames31_ES5.js
index fb7d651364..f8e3460330 100644
--- a/tests/baselines/reference/computedPropertyNames31_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames31_ES5.js
@@ -19,8 +19,7 @@ class C extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/computedPropertyNames43_ES5.js b/tests/baselines/reference/computedPropertyNames43_ES5.js
index e51df61a8c..c3b7f6a71d 100644
--- a/tests/baselines/reference/computedPropertyNames43_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames43_ES5.js
@@ -16,8 +16,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/computedPropertyNames44_ES5.js b/tests/baselines/reference/computedPropertyNames44_ES5.js
index 5efc5a1149..1186f0caef 100644
--- a/tests/baselines/reference/computedPropertyNames44_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames44_ES5.js
@@ -15,8 +15,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/computedPropertyNames45_ES5.js b/tests/baselines/reference/computedPropertyNames45_ES5.js
index d7fb6f3540..ce948e5820 100644
--- a/tests/baselines/reference/computedPropertyNames45_ES5.js
+++ b/tests/baselines/reference/computedPropertyNames45_ES5.js
@@ -16,8 +16,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/conditionalOperatorWithIdenticalBCT.js b/tests/baselines/reference/conditionalOperatorWithIdenticalBCT.js
index 18c09a500a..a493a5cfab 100644
--- a/tests/baselines/reference/conditionalOperatorWithIdenticalBCT.js
+++ b/tests/baselines/reference/conditionalOperatorWithIdenticalBCT.js
@@ -51,8 +51,7 @@ var result11: any = true ? 1 : 'string';
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 //Cond ? Expr1 : Expr2,  Expr1 and Expr2 have identical best common type
 var X = (function () {
diff --git a/tests/baselines/reference/conditionalOperatorWithoutIdenticalBCT.js b/tests/baselines/reference/conditionalOperatorWithoutIdenticalBCT.js
index 62b887d7e6..3d75eb0507 100644
--- a/tests/baselines/reference/conditionalOperatorWithoutIdenticalBCT.js
+++ b/tests/baselines/reference/conditionalOperatorWithoutIdenticalBCT.js
@@ -27,8 +27,7 @@ var result61: (t: X) => number| string = true ? (m) => m.propertyX1 : (n) => n.p
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 //Cond ? Expr1 : Expr2,  Expr1 and Expr2 have no identical best common type
 var X = (function () {
diff --git a/tests/baselines/reference/constantOverloadFunction.js b/tests/baselines/reference/constantOverloadFunction.js
index aa89c619e7..45c0fe9ff0 100644
--- a/tests/baselines/reference/constantOverloadFunction.js
+++ b/tests/baselines/reference/constantOverloadFunction.js
@@ -17,8 +17,7 @@ function foo(tagName: any): Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/constantOverloadFunctionNoSubtypeError.js b/tests/baselines/reference/constantOverloadFunctionNoSubtypeError.js
index 529f888bfc..946f819637 100644
--- a/tests/baselines/reference/constantOverloadFunctionNoSubtypeError.js
+++ b/tests/baselines/reference/constantOverloadFunctionNoSubtypeError.js
@@ -18,8 +18,7 @@ function foo(tagName: any): Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/constraintCheckInGenericBaseTypeReference.js b/tests/baselines/reference/constraintCheckInGenericBaseTypeReference.js
index 22b77ba681..9cf9d71f7a 100644
--- a/tests/baselines/reference/constraintCheckInGenericBaseTypeReference.js
+++ b/tests/baselines/reference/constraintCheckInGenericBaseTypeReference.js
@@ -23,8 +23,7 @@ class Container {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // No errors
 var Constraint = (function () {
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js
index c1c10ead1e..38b7b7fc19 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance2.js
@@ -74,8 +74,7 @@ interface I extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance3.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance3.js
index 12907c6d03..7d07c1a171 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance3.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance3.js
@@ -117,8 +117,7 @@ module Errors {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Errors;
 (function (Errors) {
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance4.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance4.js
index ef03802a17..ba341eec61 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance4.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance4.js
@@ -64,8 +64,7 @@ interface I extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js
index 9964a3464a..304b5cafd6 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance5.js
@@ -54,8 +54,7 @@ interface I extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/constructSignatureAssignabilityInInheritance6.js b/tests/baselines/reference/constructSignatureAssignabilityInInheritance6.js
index 4cf9b7d71f..99c885f971 100644
--- a/tests/baselines/reference/constructSignatureAssignabilityInInheritance6.js
+++ b/tests/baselines/reference/constructSignatureAssignabilityInInheritance6.js
@@ -57,8 +57,7 @@ interface I9<T> extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/constructorArgs.js b/tests/baselines/reference/constructorArgs.js
index 93a47178d5..6fc3511b70 100644
--- a/tests/baselines/reference/constructorArgs.js
+++ b/tests/baselines/reference/constructorArgs.js
@@ -19,8 +19,7 @@ class Sub extends Super {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Super = (function () {
     function Super(value) {
diff --git a/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType.js b/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType.js
index 9c92f31ce9..305b3e54ea 100644
--- a/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType.js
+++ b/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType.js
@@ -23,8 +23,7 @@ class Derived2 extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType2.js b/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType2.js
index 61cf399f61..b2bf377f0c 100644
--- a/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType2.js
+++ b/tests/baselines/reference/constructorFunctionTypeIsAssignableToBaseType2.js
@@ -37,8 +37,7 @@ class Derived2 extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(x) {
diff --git a/tests/baselines/reference/constructorHasPrototypeProperty.js b/tests/baselines/reference/constructorHasPrototypeProperty.js
index 47020120f9..a1bdee8e7d 100644
--- a/tests/baselines/reference/constructorHasPrototypeProperty.js
+++ b/tests/baselines/reference/constructorHasPrototypeProperty.js
@@ -35,8 +35,7 @@ module Generic {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var NonGeneric;
 (function (NonGeneric) {
diff --git a/tests/baselines/reference/constructorOverloads2.js b/tests/baselines/reference/constructorOverloads2.js
index 16da3f0fa0..d95477d84f 100644
--- a/tests/baselines/reference/constructorOverloads2.js
+++ b/tests/baselines/reference/constructorOverloads2.js
@@ -29,8 +29,7 @@ f1.bar1();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var FooBase = (function () {
     function FooBase(x) {
diff --git a/tests/baselines/reference/constructorOverloads3.js b/tests/baselines/reference/constructorOverloads3.js
index f4299466aa..c7e4e41131 100644
--- a/tests/baselines/reference/constructorOverloads3.js
+++ b/tests/baselines/reference/constructorOverloads3.js
@@ -26,8 +26,7 @@ f1.bar1();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function (_super) {
     __extends(Foo, _super);
diff --git a/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js b/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js
index 01a1880ffd..5a61d4d5d7 100644
--- a/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js
+++ b/tests/baselines/reference/constructorWithIncompleteTypeAnnotation.js
@@ -283,8 +283,7 @@ TypeScriptAllInOne.Program.Main();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var fs = module;
 ("fs");
diff --git a/tests/baselines/reference/contextualTypingArrayOfLambdas.js b/tests/baselines/reference/contextualTypingArrayOfLambdas.js
index e24ae90176..59da607079 100644
--- a/tests/baselines/reference/contextualTypingArrayOfLambdas.js
+++ b/tests/baselines/reference/contextualTypingArrayOfLambdas.js
@@ -18,8 +18,7 @@ var xs = [(x: A) => { }, (x: B) => { }, (x: C) => { }];
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/contextualTypingOfConditionalExpression.js b/tests/baselines/reference/contextualTypingOfConditionalExpression.js
index 72c15455e8..a0f8ea0a4c 100644
--- a/tests/baselines/reference/contextualTypingOfConditionalExpression.js
+++ b/tests/baselines/reference/contextualTypingOfConditionalExpression.js
@@ -18,8 +18,7 @@ var x2: (a: A) => void = true ? (a) => a.foo : (b) => b.foo;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x = true ? function (a) { return a.toExponential(); } : function (b) { return b.toFixed(); };
 var A = (function () {
diff --git a/tests/baselines/reference/contextualTypingOfConditionalExpression2.js b/tests/baselines/reference/contextualTypingOfConditionalExpression2.js
index 4e6b95a685..2833ed37d4 100644
--- a/tests/baselines/reference/contextualTypingOfConditionalExpression2.js
+++ b/tests/baselines/reference/contextualTypingOfConditionalExpression2.js
@@ -16,8 +16,7 @@ var x2: (a: A) => void = true ? (a: C) => a.foo : (b: number) => { };
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/crashInsourcePropertyIsRelatableToTargetProperty.js b/tests/baselines/reference/crashInsourcePropertyIsRelatableToTargetProperty.js
index 17c9ac649d..332f4897fc 100644
--- a/tests/baselines/reference/crashInsourcePropertyIsRelatableToTargetProperty.js
+++ b/tests/baselines/reference/crashInsourcePropertyIsRelatableToTargetProperty.js
@@ -14,8 +14,7 @@ var a: D = foo("hi", []);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/declFileForFunctionTypeAsTypeParameter.js b/tests/baselines/reference/declFileForFunctionTypeAsTypeParameter.js
index 134bacd605..0f13824fc4 100644
--- a/tests/baselines/reference/declFileForFunctionTypeAsTypeParameter.js
+++ b/tests/baselines/reference/declFileForFunctionTypeAsTypeParameter.js
@@ -13,8 +13,7 @@ interface I extends X<() => number> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var X = (function () {
     function X() {
diff --git a/tests/baselines/reference/declFileGenericClassWithGenericExtendedClass.js b/tests/baselines/reference/declFileGenericClassWithGenericExtendedClass.js
index 23630ba521..caaba28859 100644
--- a/tests/baselines/reference/declFileGenericClassWithGenericExtendedClass.js
+++ b/tests/baselines/reference/declFileGenericClassWithGenericExtendedClass.js
@@ -16,8 +16,7 @@ class Baz implements IBar<Baz> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/declFileGenericType.js b/tests/baselines/reference/declFileGenericType.js
index dfbe147a78..b67bacebb1 100644
--- a/tests/baselines/reference/declFileGenericType.js
+++ b/tests/baselines/reference/declFileGenericType.js
@@ -43,8 +43,7 @@ export var j = C.F6;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C;
 (function (C) {
diff --git a/tests/baselines/reference/declFileGenericType2.js b/tests/baselines/reference/declFileGenericType2.js
index 03649af4ba..416e0f6737 100644
--- a/tests/baselines/reference/declFileGenericType2.js
+++ b/tests/baselines/reference/declFileGenericType2.js
@@ -46,8 +46,7 @@ module templa.dom.mvc.composite {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // Module
 var templa;
diff --git a/tests/baselines/reference/declFileWithClassNameConflictingWithClassReferredByExtendsClause.js b/tests/baselines/reference/declFileWithClassNameConflictingWithClassReferredByExtendsClause.js
index 8881122839..e21c28138a 100644
--- a/tests/baselines/reference/declFileWithClassNameConflictingWithClassReferredByExtendsClause.js
+++ b/tests/baselines/reference/declFileWithClassNameConflictingWithClassReferredByExtendsClause.js
@@ -24,8 +24,7 @@ module X.Y.base.Z {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var X;
 (function (X) {
diff --git a/tests/baselines/reference/declFileWithExtendsClauseThatHasItsContainerNameConflict.js b/tests/baselines/reference/declFileWithExtendsClauseThatHasItsContainerNameConflict.js
index c06461e89f..587b8ff1e2 100644
--- a/tests/baselines/reference/declFileWithExtendsClauseThatHasItsContainerNameConflict.js
+++ b/tests/baselines/reference/declFileWithExtendsClauseThatHasItsContainerNameConflict.js
@@ -22,8 +22,7 @@ module A.B.C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A;
 (function (A) {
diff --git a/tests/baselines/reference/declarationEmit_nameConflicts3.js b/tests/baselines/reference/declarationEmit_nameConflicts3.js
index ee21d9a408..07299132bd 100644
--- a/tests/baselines/reference/declarationEmit_nameConflicts3.js
+++ b/tests/baselines/reference/declarationEmit_nameConflicts3.js
@@ -30,8 +30,7 @@ module M.P {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/declarationEmit_protectedMembers.js b/tests/baselines/reference/declarationEmit_protectedMembers.js
index faa1dc298e..536f4f4aff 100644
--- a/tests/baselines/reference/declarationEmit_protectedMembers.js
+++ b/tests/baselines/reference/declarationEmit_protectedMembers.js
@@ -54,8 +54,7 @@ class C4 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // Class with protected members
 var C1 = (function () {
diff --git a/tests/baselines/reference/declareDottedExtend.js b/tests/baselines/reference/declareDottedExtend.js
index 2579a5557f..030e5048ef 100644
--- a/tests/baselines/reference/declareDottedExtend.js
+++ b/tests/baselines/reference/declareDottedExtend.js
@@ -15,8 +15,7 @@ class E extends A.B.C{ }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var ab = A.B;
 var D = (function (_super) {
diff --git a/tests/baselines/reference/decoratorOnClassMethod12.js b/tests/baselines/reference/decoratorOnClassMethod12.js
index aa938eaaaf..05c4f28529 100644
--- a/tests/baselines/reference/decoratorOnClassMethod12.js
+++ b/tests/baselines/reference/decoratorOnClassMethod12.js
@@ -13,8 +13,7 @@ module M {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
     if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
diff --git a/tests/baselines/reference/derivedClassConstructorWithoutSuperCall.js b/tests/baselines/reference/derivedClassConstructorWithoutSuperCall.js
index 37dc2db870..b9090176ad 100644
--- a/tests/baselines/reference/derivedClassConstructorWithoutSuperCall.js
+++ b/tests/baselines/reference/derivedClassConstructorWithoutSuperCall.js
@@ -37,8 +37,7 @@ class Derived4<T> extends Base2<T> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassFunctionOverridesBaseClassAccessor.js b/tests/baselines/reference/derivedClassFunctionOverridesBaseClassAccessor.js
index eaf7dfd569..64da47e68e 100644
--- a/tests/baselines/reference/derivedClassFunctionOverridesBaseClassAccessor.js
+++ b/tests/baselines/reference/derivedClassFunctionOverridesBaseClassAccessor.js
@@ -18,8 +18,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassIncludesInheritedMembers.js b/tests/baselines/reference/derivedClassIncludesInheritedMembers.js
index b83255ccf9..0538ba9b54 100644
--- a/tests/baselines/reference/derivedClassIncludesInheritedMembers.js
+++ b/tests/baselines/reference/derivedClassIncludesInheritedMembers.js
@@ -44,8 +44,7 @@ var r8 = d2[1];
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(x) {
diff --git a/tests/baselines/reference/derivedClassOverridesIndexersWithAssignmentCompatibility.js b/tests/baselines/reference/derivedClassOverridesIndexersWithAssignmentCompatibility.js
index 1fe59d7804..a575c9bb18 100644
--- a/tests/baselines/reference/derivedClassOverridesIndexersWithAssignmentCompatibility.js
+++ b/tests/baselines/reference/derivedClassOverridesIndexersWithAssignmentCompatibility.js
@@ -21,8 +21,7 @@ class Derived2 extends Base2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassOverridesPrivateFunction1.js b/tests/baselines/reference/derivedClassOverridesPrivateFunction1.js
index b9cd6df033..7e11209b8f 100644
--- a/tests/baselines/reference/derivedClassOverridesPrivateFunction1.js
+++ b/tests/baselines/reference/derivedClassOverridesPrivateFunction1.js
@@ -19,8 +19,7 @@ new DerivedClass();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var BaseClass = (function () {
     function BaseClass() {
diff --git a/tests/baselines/reference/derivedClassOverridesPrivates.js b/tests/baselines/reference/derivedClassOverridesPrivates.js
index 2cc8360a80..6662b5013d 100644
--- a/tests/baselines/reference/derivedClassOverridesPrivates.js
+++ b/tests/baselines/reference/derivedClassOverridesPrivates.js
@@ -19,8 +19,7 @@ class Derived2 extends Base2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassOverridesProtectedMembers.js b/tests/baselines/reference/derivedClassOverridesProtectedMembers.js
index 48ee6eded6..21f2ce8788 100644
--- a/tests/baselines/reference/derivedClassOverridesProtectedMembers.js
+++ b/tests/baselines/reference/derivedClassOverridesProtectedMembers.js
@@ -40,8 +40,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x;
 var y;
diff --git a/tests/baselines/reference/derivedClassOverridesProtectedMembers2.js b/tests/baselines/reference/derivedClassOverridesProtectedMembers2.js
index fca27b0de0..b5fe3e93af 100644
--- a/tests/baselines/reference/derivedClassOverridesProtectedMembers2.js
+++ b/tests/baselines/reference/derivedClassOverridesProtectedMembers2.js
@@ -67,8 +67,7 @@ var r8 = d2[1];
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x;
 var y;
diff --git a/tests/baselines/reference/derivedClassOverridesProtectedMembers3.js b/tests/baselines/reference/derivedClassOverridesProtectedMembers3.js
index 2a102d55ea..c4dc1d0e9d 100644
--- a/tests/baselines/reference/derivedClassOverridesProtectedMembers3.js
+++ b/tests/baselines/reference/derivedClassOverridesProtectedMembers3.js
@@ -75,8 +75,7 @@ class Derived10 extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x;
 var y;
diff --git a/tests/baselines/reference/derivedClassOverridesProtectedMembers4.js b/tests/baselines/reference/derivedClassOverridesProtectedMembers4.js
index 5145f3919a..f25c3b792d 100644
--- a/tests/baselines/reference/derivedClassOverridesProtectedMembers4.js
+++ b/tests/baselines/reference/derivedClassOverridesProtectedMembers4.js
@@ -18,8 +18,7 @@ class Derived2 extends Derived1 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x;
 var y;
diff --git a/tests/baselines/reference/derivedClassOverridesPublicMembers.js b/tests/baselines/reference/derivedClassOverridesPublicMembers.js
index 0529189e4c..5125be4eee 100644
--- a/tests/baselines/reference/derivedClassOverridesPublicMembers.js
+++ b/tests/baselines/reference/derivedClassOverridesPublicMembers.js
@@ -66,8 +66,7 @@ var r8 = d2[1];
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x;
 var y;
diff --git a/tests/baselines/reference/derivedClassOverridesWithoutSubtype.js b/tests/baselines/reference/derivedClassOverridesWithoutSubtype.js
index 5cb746bfdd..9762c88035 100644
--- a/tests/baselines/reference/derivedClassOverridesWithoutSubtype.js
+++ b/tests/baselines/reference/derivedClassOverridesWithoutSubtype.js
@@ -27,8 +27,7 @@ class Derived2 extends Base2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassParameterProperties.js b/tests/baselines/reference/derivedClassParameterProperties.js
index dd5b206ecd..55c0a312b7 100644
--- a/tests/baselines/reference/derivedClassParameterProperties.js
+++ b/tests/baselines/reference/derivedClassParameterProperties.js
@@ -99,8 +99,7 @@ class Derived10<T> extends Base2<T> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassSuperCallsInNonConstructorMembers.js b/tests/baselines/reference/derivedClassSuperCallsInNonConstructorMembers.js
index d2914cd694..0c214d42fe 100644
--- a/tests/baselines/reference/derivedClassSuperCallsInNonConstructorMembers.js
+++ b/tests/baselines/reference/derivedClassSuperCallsInNonConstructorMembers.js
@@ -36,8 +36,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassSuperCallsWithThisArg.js b/tests/baselines/reference/derivedClassSuperCallsWithThisArg.js
index 7c7e9b40ce..a81a092fa5 100644
--- a/tests/baselines/reference/derivedClassSuperCallsWithThisArg.js
+++ b/tests/baselines/reference/derivedClassSuperCallsWithThisArg.js
@@ -32,8 +32,7 @@ class Derived4 extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(a) {
diff --git a/tests/baselines/reference/derivedClassTransitivity.js b/tests/baselines/reference/derivedClassTransitivity.js
index ad4f3e481a..de7669a71b 100644
--- a/tests/baselines/reference/derivedClassTransitivity.js
+++ b/tests/baselines/reference/derivedClassTransitivity.js
@@ -25,8 +25,7 @@ var r2 = e.foo('');
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/derivedClassTransitivity2.js b/tests/baselines/reference/derivedClassTransitivity2.js
index efeb25195f..22e930ab7f 100644
--- a/tests/baselines/reference/derivedClassTransitivity2.js
+++ b/tests/baselines/reference/derivedClassTransitivity2.js
@@ -25,8 +25,7 @@ var r2 = e.foo(1, '');
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/derivedClassTransitivity3.js b/tests/baselines/reference/derivedClassTransitivity3.js
index 8befbf1873..a1aa3a978e 100644
--- a/tests/baselines/reference/derivedClassTransitivity3.js
+++ b/tests/baselines/reference/derivedClassTransitivity3.js
@@ -25,8 +25,7 @@ var r2 = e.foo('', 1);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/derivedClassTransitivity4.js b/tests/baselines/reference/derivedClassTransitivity4.js
index 546c7e4a84..a4d319707c 100644
--- a/tests/baselines/reference/derivedClassTransitivity4.js
+++ b/tests/baselines/reference/derivedClassTransitivity4.js
@@ -25,8 +25,7 @@ var r2 = e.foo('');
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/derivedClassWithAny.js b/tests/baselines/reference/derivedClassWithAny.js
index 6f9ef48462..123853f3af 100644
--- a/tests/baselines/reference/derivedClassWithAny.js
+++ b/tests/baselines/reference/derivedClassWithAny.js
@@ -63,8 +63,7 @@ var r = c.foo(); // e.foo would return string
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingProtectedInstance.js b/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingProtectedInstance.js
index bf8b1b51cd..3454c60f88 100644
--- a/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingProtectedInstance.js
+++ b/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingProtectedInstance.js
@@ -26,8 +26,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingPublicInstance.js b/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingPublicInstance.js
index 131c529f3b..7de92c9cb2 100644
--- a/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingPublicInstance.js
+++ b/tests/baselines/reference/derivedClassWithPrivateInstanceShadowingPublicInstance.js
@@ -36,8 +36,7 @@ Derived.a = 2; // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassWithPrivateStaticShadowingProtectedStatic.js b/tests/baselines/reference/derivedClassWithPrivateStaticShadowingProtectedStatic.js
index d661eeadc0..36d2b7d2dc 100644
--- a/tests/baselines/reference/derivedClassWithPrivateStaticShadowingProtectedStatic.js
+++ b/tests/baselines/reference/derivedClassWithPrivateStaticShadowingProtectedStatic.js
@@ -25,8 +25,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassWithPrivateStaticShadowingPublicStatic.js b/tests/baselines/reference/derivedClassWithPrivateStaticShadowingPublicStatic.js
index c3fc34b21c..36080385b3 100644
--- a/tests/baselines/reference/derivedClassWithPrivateStaticShadowingPublicStatic.js
+++ b/tests/baselines/reference/derivedClassWithPrivateStaticShadowingPublicStatic.js
@@ -37,8 +37,7 @@ Derived.a = 2; // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedClassWithoutExplicitConstructor.js b/tests/baselines/reference/derivedClassWithoutExplicitConstructor.js
index 16b9b110a5..27a634ab2d 100644
--- a/tests/baselines/reference/derivedClassWithoutExplicitConstructor.js
+++ b/tests/baselines/reference/derivedClassWithoutExplicitConstructor.js
@@ -29,8 +29,7 @@ var d2 = new D(new Date()); // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(x) {
diff --git a/tests/baselines/reference/derivedClassWithoutExplicitConstructor2.js b/tests/baselines/reference/derivedClassWithoutExplicitConstructor2.js
index 6e413752f1..82c5eec1d7 100644
--- a/tests/baselines/reference/derivedClassWithoutExplicitConstructor2.js
+++ b/tests/baselines/reference/derivedClassWithoutExplicitConstructor2.js
@@ -37,8 +37,7 @@ var d4 = new D(new Date(), new Date(), new Date());
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(x) {
diff --git a/tests/baselines/reference/derivedClassWithoutExplicitConstructor3.js b/tests/baselines/reference/derivedClassWithoutExplicitConstructor3.js
index b72fdb1503..4bfa7c8157 100644
--- a/tests/baselines/reference/derivedClassWithoutExplicitConstructor3.js
+++ b/tests/baselines/reference/derivedClassWithoutExplicitConstructor3.js
@@ -51,8 +51,7 @@ var d3 = new D2(new Date(), new Date()); // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(x) {
diff --git a/tests/baselines/reference/derivedClasses.js b/tests/baselines/reference/derivedClasses.js
index 7221031cb8..214c65bde6 100644
--- a/tests/baselines/reference/derivedClasses.js
+++ b/tests/baselines/reference/derivedClasses.js
@@ -34,8 +34,7 @@ b.hue();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Red = (function (_super) {
     __extends(Red, _super);
diff --git a/tests/baselines/reference/derivedGenericClassWithAny.js b/tests/baselines/reference/derivedGenericClassWithAny.js
index b5bfbd5e5d..15835e78bd 100644
--- a/tests/baselines/reference/derivedGenericClassWithAny.js
+++ b/tests/baselines/reference/derivedGenericClassWithAny.js
@@ -46,8 +46,7 @@ var r = c.foo(); // e.foo would return string
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/derivedTypeAccessesHiddenBaseCallViaSuperPropertyAccess.js b/tests/baselines/reference/derivedTypeAccessesHiddenBaseCallViaSuperPropertyAccess.js
index 564a51f2b1..0839b93971 100644
--- a/tests/baselines/reference/derivedTypeAccessesHiddenBaseCallViaSuperPropertyAccess.js
+++ b/tests/baselines/reference/derivedTypeAccessesHiddenBaseCallViaSuperPropertyAccess.js
@@ -21,8 +21,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/derivedTypeDoesNotRequireExtendsClause.js b/tests/baselines/reference/derivedTypeDoesNotRequireExtendsClause.js
index f981a5e6e5..f00c32114c 100644
--- a/tests/baselines/reference/derivedTypeDoesNotRequireExtendsClause.js
+++ b/tests/baselines/reference/derivedTypeDoesNotRequireExtendsClause.js
@@ -24,8 +24,7 @@ var r: Base[] = [d1, d2];
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/destructuringParameterDeclaration5.js b/tests/baselines/reference/destructuringParameterDeclaration5.js
index 7540302599..38366ca67b 100644
--- a/tests/baselines/reference/destructuringParameterDeclaration5.js
+++ b/tests/baselines/reference/destructuringParameterDeclaration5.js
@@ -55,8 +55,7 @@ d3({ y: "world" });
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Class = (function () {
     function Class() {
diff --git a/tests/baselines/reference/emitThisInSuperMethodCall.js b/tests/baselines/reference/emitThisInSuperMethodCall.js
index 9224e156de..f5cff5a8fa 100644
--- a/tests/baselines/reference/emitThisInSuperMethodCall.js
+++ b/tests/baselines/reference/emitThisInSuperMethodCall.js
@@ -31,8 +31,7 @@ class RegisteredUser extends User {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var User = (function () {
     function User() {
diff --git a/tests/baselines/reference/errorForwardReferenceForwadingConstructor.js b/tests/baselines/reference/errorForwardReferenceForwadingConstructor.js
index f1a0d741a5..0b30745fa1 100644
--- a/tests/baselines/reference/errorForwardReferenceForwadingConstructor.js
+++ b/tests/baselines/reference/errorForwardReferenceForwadingConstructor.js
@@ -15,8 +15,7 @@ class derived extends base { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function f() {
     var d1 = new derived();
diff --git a/tests/baselines/reference/errorSuperCalls.js b/tests/baselines/reference/errorSuperCalls.js
index bd692f35fa..d2d4911c76 100644
--- a/tests/baselines/reference/errorSuperCalls.js
+++ b/tests/baselines/reference/errorSuperCalls.js
@@ -78,8 +78,7 @@ class OtherDerived extends OtherBase {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 //super call in class constructor with no base type
 var NoBase = (function () {
diff --git a/tests/baselines/reference/errorSuperPropertyAccess.js b/tests/baselines/reference/errorSuperPropertyAccess.js
index abf077d2b8..57a574d8a0 100644
--- a/tests/baselines/reference/errorSuperPropertyAccess.js
+++ b/tests/baselines/reference/errorSuperPropertyAccess.js
@@ -132,8 +132,7 @@ var obj = { n: super.wat, p: super.foo() };
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 //super property access in constructor of class with no base type
 //super property access in instance member function of class with no base type
diff --git a/tests/baselines/reference/errorsInGenericTypeReference.js b/tests/baselines/reference/errorsInGenericTypeReference.js
index 0ba69b601a..42c7456be6 100644
--- a/tests/baselines/reference/errorsInGenericTypeReference.js
+++ b/tests/baselines/reference/errorsInGenericTypeReference.js
@@ -76,8 +76,7 @@ interface testInterface2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/es6ClassSuperCodegenBug.js b/tests/baselines/reference/es6ClassSuperCodegenBug.js
index a374778ef4..62c96f6260 100644
--- a/tests/baselines/reference/es6ClassSuperCodegenBug.js
+++ b/tests/baselines/reference/es6ClassSuperCodegenBug.js
@@ -17,8 +17,7 @@ class B extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(str1, str2) {
diff --git a/tests/baselines/reference/es6ClassTest.js b/tests/baselines/reference/es6ClassTest.js
index bf65840e31..9247dfde1c 100644
--- a/tests/baselines/reference/es6ClassTest.js
+++ b/tests/baselines/reference/es6ClassTest.js
@@ -88,8 +88,7 @@ declare module AmbientMod {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Bar = (function () {
     function Bar(n) {
diff --git a/tests/baselines/reference/es6ClassTest2.js b/tests/baselines/reference/es6ClassTest2.js
index 40f1c15c8f..20200a692f 100644
--- a/tests/baselines/reference/es6ClassTest2.js
+++ b/tests/baselines/reference/es6ClassTest2.js
@@ -162,8 +162,7 @@ var ccwc = new ChildClassWithoutConstructor(1, "s");
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var BasicMonster = (function () {
     function BasicMonster(name, health) {
diff --git a/tests/baselines/reference/es6ClassTest7.js b/tests/baselines/reference/es6ClassTest7.js
index c4f7e83b9a..970e9c4fd9 100644
--- a/tests/baselines/reference/es6ClassTest7.js
+++ b/tests/baselines/reference/es6ClassTest7.js
@@ -12,8 +12,7 @@ class Bar extends M.Foo {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Bar = (function (_super) {
     __extends(Bar, _super);
diff --git a/tests/baselines/reference/exportAssignmentOfGenericType1.js b/tests/baselines/reference/exportAssignmentOfGenericType1.js
index 983c328cd9..59fa01f2ca 100644
--- a/tests/baselines/reference/exportAssignmentOfGenericType1.js
+++ b/tests/baselines/reference/exportAssignmentOfGenericType1.js
@@ -26,8 +26,7 @@ define(["require", "exports"], function (require, exports) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 define(["require", "exports", "exportAssignmentOfGenericType1_0"], function (require, exports, q) {
     var M = (function (_super) {
diff --git a/tests/baselines/reference/exportDeclarationInInternalModule.js b/tests/baselines/reference/exportDeclarationInInternalModule.js
index 9894f1fb19..4a1ee9b739 100644
--- a/tests/baselines/reference/exportDeclarationInInternalModule.js
+++ b/tests/baselines/reference/exportDeclarationInInternalModule.js
@@ -22,8 +22,7 @@ var a: Bbb.SomeType;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Bbb = (function () {
     function Bbb() {
diff --git a/tests/baselines/reference/extBaseClass1.js b/tests/baselines/reference/extBaseClass1.js
index 9e7421b906..07923eccc8 100644
--- a/tests/baselines/reference/extBaseClass1.js
+++ b/tests/baselines/reference/extBaseClass1.js
@@ -23,8 +23,7 @@ module N {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/extBaseClass2.js b/tests/baselines/reference/extBaseClass2.js
index e5a717bca8..6e9972c3f2 100644
--- a/tests/baselines/reference/extBaseClass2.js
+++ b/tests/baselines/reference/extBaseClass2.js
@@ -14,8 +14,7 @@ module M {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var N;
 (function (N) {
diff --git a/tests/baselines/reference/extendAndImplementTheSameBaseType.js b/tests/baselines/reference/extendAndImplementTheSameBaseType.js
index c69315dbd6..6a631ceebf 100644
--- a/tests/baselines/reference/extendAndImplementTheSameBaseType.js
+++ b/tests/baselines/reference/extendAndImplementTheSameBaseType.js
@@ -17,8 +17,7 @@ d.foo;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/extendAndImplementTheSameBaseType2.js b/tests/baselines/reference/extendAndImplementTheSameBaseType2.js
index 06ea74880c..42cf785c0b 100644
--- a/tests/baselines/reference/extendAndImplementTheSameBaseType2.js
+++ b/tests/baselines/reference/extendAndImplementTheSameBaseType2.js
@@ -20,8 +20,7 @@ var r4: number = d.bar();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/extendBaseClassBeforeItsDeclared.js b/tests/baselines/reference/extendBaseClassBeforeItsDeclared.js
index 7598d771ba..d8c54b58d7 100644
--- a/tests/baselines/reference/extendBaseClassBeforeItsDeclared.js
+++ b/tests/baselines/reference/extendBaseClassBeforeItsDeclared.js
@@ -7,8 +7,7 @@ class base { constructor (public n: number) { } }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var derived = (function (_super) {
     __extends(derived, _super);
diff --git a/tests/baselines/reference/extendNonClassSymbol1.js b/tests/baselines/reference/extendNonClassSymbol1.js
index 59da2d7ca2..2940868606 100644
--- a/tests/baselines/reference/extendNonClassSymbol1.js
+++ b/tests/baselines/reference/extendNonClassSymbol1.js
@@ -7,8 +7,7 @@ class C extends x { } // error, could not find symbol xs
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/extendNonClassSymbol2.js b/tests/baselines/reference/extendNonClassSymbol2.js
index 830994e3d2..a65eeca612 100644
--- a/tests/baselines/reference/extendNonClassSymbol2.js
+++ b/tests/baselines/reference/extendNonClassSymbol2.js
@@ -9,8 +9,7 @@ class C extends Foo {} // error, could not find symbol Foo
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function Foo() {
     this.x = 1;
diff --git a/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.js b/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.js
index 0bf86390b7..297a7527ec 100644
--- a/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.js
+++ b/tests/baselines/reference/extendingClassFromAliasAndUsageInIndexer.js
@@ -43,8 +43,7 @@ exports.Model = Model;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("extendingClassFromAliasAndUsageInIndexer_backbone");
 var VisualizationModel = (function (_super) {
@@ -59,8 +58,7 @@ exports.VisualizationModel = VisualizationModel;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Backbone = require("extendingClassFromAliasAndUsageInIndexer_backbone");
 var VisualizationModel = (function (_super) {
diff --git a/tests/baselines/reference/extendsClauseAlreadySeen.js b/tests/baselines/reference/extendsClauseAlreadySeen.js
index 3e7151b8e0..ed6602c116 100644
--- a/tests/baselines/reference/extendsClauseAlreadySeen.js
+++ b/tests/baselines/reference/extendsClauseAlreadySeen.js
@@ -10,8 +10,7 @@ class D extends C extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/extendsClauseAlreadySeen2.js b/tests/baselines/reference/extendsClauseAlreadySeen2.js
index 9ee428c36e..2c77f4e673 100644
--- a/tests/baselines/reference/extendsClauseAlreadySeen2.js
+++ b/tests/baselines/reference/extendsClauseAlreadySeen2.js
@@ -10,8 +10,7 @@ class D<T> extends C<number> extends C<string> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/for-inStatements.js b/tests/baselines/reference/for-inStatements.js
index 749c7b47b3..d735a37ba9 100644
--- a/tests/baselines/reference/for-inStatements.js
+++ b/tests/baselines/reference/for-inStatements.js
@@ -84,8 +84,7 @@ for (var x in Color.Blue) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var aString;
 for (aString in {}) { }
diff --git a/tests/baselines/reference/for-inStatementsInvalid.js b/tests/baselines/reference/for-inStatementsInvalid.js
index e180627279..93b9fb9b97 100644
--- a/tests/baselines/reference/for-inStatementsInvalid.js
+++ b/tests/baselines/reference/for-inStatementsInvalid.js
@@ -67,8 +67,7 @@ for (var x in i[42]) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var aNumber;
 for (aNumber in {}) { }
diff --git a/tests/baselines/reference/forStatementsMultipleInvalidDecl.js b/tests/baselines/reference/forStatementsMultipleInvalidDecl.js
index b00e8acef1..1dde998188 100644
--- a/tests/baselines/reference/forStatementsMultipleInvalidDecl.js
+++ b/tests/baselines/reference/forStatementsMultipleInvalidDecl.js
@@ -57,8 +57,7 @@ for( var m = M.A;;){}
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/functionImplementationErrors.js b/tests/baselines/reference/functionImplementationErrors.js
index 6c1daffdaf..42be5f2145 100644
--- a/tests/baselines/reference/functionImplementationErrors.js
+++ b/tests/baselines/reference/functionImplementationErrors.js
@@ -77,8 +77,7 @@ var f13 = () => {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // FunctionExpression with no return type annotation with multiple return statements with unrelated types
 var f1 = function () {
diff --git a/tests/baselines/reference/functionImplementations.js b/tests/baselines/reference/functionImplementations.js
index 0370c4c002..3fc040650e 100644
--- a/tests/baselines/reference/functionImplementations.js
+++ b/tests/baselines/reference/functionImplementations.js
@@ -160,8 +160,7 @@ var f12: (x: number) => any = x => { // should be (x: number) => Base | AnotherC
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // FunctionExpression with no return type annotation and no return statement returns void
 var v = function () { }();
diff --git a/tests/baselines/reference/functionSubtypingOfVarArgs.js b/tests/baselines/reference/functionSubtypingOfVarArgs.js
index b016897567..ddcb057090 100644
--- a/tests/baselines/reference/functionSubtypingOfVarArgs.js
+++ b/tests/baselines/reference/functionSubtypingOfVarArgs.js
@@ -18,8 +18,7 @@ class StringEvent extends EventBase { // should work
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var EventBase = (function () {
     function EventBase() {
diff --git a/tests/baselines/reference/functionSubtypingOfVarArgs2.js b/tests/baselines/reference/functionSubtypingOfVarArgs2.js
index 7efd35cc2d..d04a5b97da 100644
--- a/tests/baselines/reference/functionSubtypingOfVarArgs2.js
+++ b/tests/baselines/reference/functionSubtypingOfVarArgs2.js
@@ -18,8 +18,7 @@ class StringEvent extends EventBase {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var EventBase = (function () {
     function EventBase() {
diff --git a/tests/baselines/reference/generatedContextualTyping.js b/tests/baselines/reference/generatedContextualTyping.js
index 3c2c704ddb..1f7d2b8035 100644
--- a/tests/baselines/reference/generatedContextualTyping.js
+++ b/tests/baselines/reference/generatedContextualTyping.js
@@ -358,8 +358,7 @@ var x356 = function(n: Genric<Base>) { }; x356({ func: n => { return [d1, d2]; }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/genericBaseClassLiteralProperty.js b/tests/baselines/reference/genericBaseClassLiteralProperty.js
index 5e36553146..f8a5f78e75 100644
--- a/tests/baselines/reference/genericBaseClassLiteralProperty.js
+++ b/tests/baselines/reference/genericBaseClassLiteralProperty.js
@@ -16,8 +16,7 @@ class SubClass extends BaseClass<number> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var BaseClass = (function () {
     function BaseClass() {
diff --git a/tests/baselines/reference/genericBaseClassLiteralProperty2.js b/tests/baselines/reference/genericBaseClassLiteralProperty2.js
index 8a19d857bb..d5c480955d 100644
--- a/tests/baselines/reference/genericBaseClassLiteralProperty2.js
+++ b/tests/baselines/reference/genericBaseClassLiteralProperty2.js
@@ -19,8 +19,7 @@ class DataView2 extends BaseCollection2<CollectionItem2> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var CollectionItem2 = (function () {
     function CollectionItem2() {
diff --git a/tests/baselines/reference/genericCallWithConstraintsTypeArgumentInference.js b/tests/baselines/reference/genericCallWithConstraintsTypeArgumentInference.js
index f00468dcbc..9df55756ee 100644
--- a/tests/baselines/reference/genericCallWithConstraintsTypeArgumentInference.js
+++ b/tests/baselines/reference/genericCallWithConstraintsTypeArgumentInference.js
@@ -112,8 +112,7 @@ var r11 = i.foo8(); // Base
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/genericCallWithObjectTypeArgs2.js b/tests/baselines/reference/genericCallWithObjectTypeArgs2.js
index 910e3860b4..bded01ead6 100644
--- a/tests/baselines/reference/genericCallWithObjectTypeArgs2.js
+++ b/tests/baselines/reference/genericCallWithObjectTypeArgs2.js
@@ -36,8 +36,7 @@ var r4 = f2(i); // Base => Derived
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints2.js b/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints2.js
index 9cb2425f9d..96c2f9300d 100644
--- a/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints2.js
+++ b/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints2.js
@@ -44,8 +44,7 @@ var r7 = f3(null, x => x); // any
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.js b/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.js
index 3c5a4c24b5..daaa2f5c0e 100644
--- a/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.js
+++ b/tests/baselines/reference/genericCallWithObjectTypeArgsAndConstraints3.js
@@ -42,8 +42,7 @@ var r6 = f3(x => x, null);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/genericCallbacksAndClassHierarchy.js b/tests/baselines/reference/genericCallbacksAndClassHierarchy.js
index 16abb2683e..093757d513 100644
--- a/tests/baselines/reference/genericCallbacksAndClassHierarchy.js
+++ b/tests/baselines/reference/genericCallbacksAndClassHierarchy.js
@@ -27,8 +27,7 @@ module M {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/genericClassInheritsConstructorFromNonGenericClass.js b/tests/baselines/reference/genericClassInheritsConstructorFromNonGenericClass.js
index 22bb975e7d..f77f60a2fb 100644
--- a/tests/baselines/reference/genericClassInheritsConstructorFromNonGenericClass.js
+++ b/tests/baselines/reference/genericClassInheritsConstructorFromNonGenericClass.js
@@ -9,8 +9,7 @@ class C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function (_super) {
     __extends(A, _super);
diff --git a/tests/baselines/reference/genericClassPropertyInheritanceSpecialization.js b/tests/baselines/reference/genericClassPropertyInheritanceSpecialization.js
index 43d1e53a61..6926174724 100644
--- a/tests/baselines/reference/genericClassPropertyInheritanceSpecialization.js
+++ b/tests/baselines/reference/genericClassPropertyInheritanceSpecialization.js
@@ -79,8 +79,7 @@ class ViewModel<TValue> implements Contract<TValue> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Portal;
 (function (Portal) {
diff --git a/tests/baselines/reference/genericClassStaticMethod.js b/tests/baselines/reference/genericClassStaticMethod.js
index 23e1874c0e..aed721aa7d 100644
--- a/tests/baselines/reference/genericClassStaticMethod.js
+++ b/tests/baselines/reference/genericClassStaticMethod.js
@@ -14,8 +14,7 @@ class Bar<T> extends Foo<T> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/genericClasses3.js b/tests/baselines/reference/genericClasses3.js
index 373052d78e..14ffab2f6f 100644
--- a/tests/baselines/reference/genericClasses3.js
+++ b/tests/baselines/reference/genericClasses3.js
@@ -21,8 +21,7 @@ var z = v2.b;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B = (function () {
     function B() {
diff --git a/tests/baselines/reference/genericConstraintOnExtendedBuiltinTypes.js b/tests/baselines/reference/genericConstraintOnExtendedBuiltinTypes.js
index 561c24cd50..b4e5693377 100644
--- a/tests/baselines/reference/genericConstraintOnExtendedBuiltinTypes.js
+++ b/tests/baselines/reference/genericConstraintOnExtendedBuiltinTypes.js
@@ -30,8 +30,7 @@ module EndGate.Tweening {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var EndGate;
 (function (EndGate) {
diff --git a/tests/baselines/reference/genericConstraintOnExtendedBuiltinTypes2.js b/tests/baselines/reference/genericConstraintOnExtendedBuiltinTypes2.js
index 2420e082e3..54a807a8e8 100644
--- a/tests/baselines/reference/genericConstraintOnExtendedBuiltinTypes2.js
+++ b/tests/baselines/reference/genericConstraintOnExtendedBuiltinTypes2.js
@@ -29,8 +29,7 @@ module EndGate.Tweening {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var EndGate;
 (function (EndGate) {
diff --git a/tests/baselines/reference/genericDerivedTypeWithSpecializedBase.js b/tests/baselines/reference/genericDerivedTypeWithSpecializedBase.js
index 69ae509bf5..eb27365ebc 100644
--- a/tests/baselines/reference/genericDerivedTypeWithSpecializedBase.js
+++ b/tests/baselines/reference/genericDerivedTypeWithSpecializedBase.js
@@ -16,8 +16,7 @@ x = y;  // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/genericDerivedTypeWithSpecializedBase2.js b/tests/baselines/reference/genericDerivedTypeWithSpecializedBase2.js
index 1c4f27b5eb..be94a77885 100644
--- a/tests/baselines/reference/genericDerivedTypeWithSpecializedBase2.js
+++ b/tests/baselines/reference/genericDerivedTypeWithSpecializedBase2.js
@@ -16,8 +16,7 @@ x = y;  // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/genericPrototypeProperty2.js b/tests/baselines/reference/genericPrototypeProperty2.js
index b91b345481..cbe33431ca 100644
--- a/tests/baselines/reference/genericPrototypeProperty2.js
+++ b/tests/baselines/reference/genericPrototypeProperty2.js
@@ -19,8 +19,7 @@ class MyEventWrapper extends BaseEventWrapper {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var BaseEvent = (function () {
     function BaseEvent() {
diff --git a/tests/baselines/reference/genericPrototypeProperty3.js b/tests/baselines/reference/genericPrototypeProperty3.js
index de093886ea..6447a4e0ac 100644
--- a/tests/baselines/reference/genericPrototypeProperty3.js
+++ b/tests/baselines/reference/genericPrototypeProperty3.js
@@ -18,8 +18,7 @@ class MyEventWrapper extends BaseEventWrapper {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var BaseEvent = (function () {
     function BaseEvent() {
diff --git a/tests/baselines/reference/genericRecursiveImplicitConstructorErrors2.js b/tests/baselines/reference/genericRecursiveImplicitConstructorErrors2.js
index b73239626d..a1f7566f1c 100644
--- a/tests/baselines/reference/genericRecursiveImplicitConstructorErrors2.js
+++ b/tests/baselines/reference/genericRecursiveImplicitConstructorErrors2.js
@@ -30,8 +30,7 @@ module TypeScript2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var TypeScript2;
 (function (TypeScript2) {
diff --git a/tests/baselines/reference/genericRecursiveImplicitConstructorErrors3.js b/tests/baselines/reference/genericRecursiveImplicitConstructorErrors3.js
index 0d4a3315ac..a0229e1992 100644
--- a/tests/baselines/reference/genericRecursiveImplicitConstructorErrors3.js
+++ b/tests/baselines/reference/genericRecursiveImplicitConstructorErrors3.js
@@ -34,8 +34,7 @@ module TypeScript {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var TypeScript;
 (function (TypeScript) {
diff --git a/tests/baselines/reference/genericTypeAssertions2.js b/tests/baselines/reference/genericTypeAssertions2.js
index a3b88f599b..22ff708592 100644
--- a/tests/baselines/reference/genericTypeAssertions2.js
+++ b/tests/baselines/reference/genericTypeAssertions2.js
@@ -17,8 +17,7 @@ var r5: A<number> = <A<number>>[]; // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/genericTypeAssertions4.js b/tests/baselines/reference/genericTypeAssertions4.js
index 95ca5482b2..d6d8672283 100644
--- a/tests/baselines/reference/genericTypeAssertions4.js
+++ b/tests/baselines/reference/genericTypeAssertions4.js
@@ -29,8 +29,7 @@ function foo2<T extends A>(x: T) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/genericTypeAssertions6.js b/tests/baselines/reference/genericTypeAssertions6.js
index d19da50668..30a5d5ff5e 100644
--- a/tests/baselines/reference/genericTypeAssertions6.js
+++ b/tests/baselines/reference/genericTypeAssertions6.js
@@ -28,8 +28,7 @@ var c: A<Date, Date> = <A<Date, Date>>b;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(x) {
diff --git a/tests/baselines/reference/genericTypeConstraints.js b/tests/baselines/reference/genericTypeConstraints.js
index 6f0f235ccb..eb8bed1fb9 100644
--- a/tests/baselines/reference/genericTypeConstraints.js
+++ b/tests/baselines/reference/genericTypeConstraints.js
@@ -17,8 +17,7 @@ class BarExtended extends Bar<FooExtended> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument.js b/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument.js
index 5ec0a25af3..0cbf358170 100644
--- a/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument.js
+++ b/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument.js
@@ -43,8 +43,7 @@ var k = <M.E>null;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument2.js b/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument2.js
index 2f36a74de7..355030caa1 100644
--- a/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument2.js
+++ b/tests/baselines/reference/genericTypeReferenceWithoutTypeArgument2.js
@@ -43,8 +43,7 @@ var k = <M.E>null;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var c;
 var a;
diff --git a/tests/baselines/reference/genericWithIndexerOfTypeParameterType2.js b/tests/baselines/reference/genericWithIndexerOfTypeParameterType2.js
index 8142cd8640..2457d4a534 100644
--- a/tests/baselines/reference/genericWithIndexerOfTypeParameterType2.js
+++ b/tests/baselines/reference/genericWithIndexerOfTypeParameterType2.js
@@ -18,8 +18,7 @@ export class ListItem extends CollectionItem {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 define(["require", "exports"], function (require, exports) {
     var Collection = (function () {
diff --git a/tests/baselines/reference/heterogeneousArrayLiterals.js b/tests/baselines/reference/heterogeneousArrayLiterals.js
index 26d1b09a6f..45ea642997 100644
--- a/tests/baselines/reference/heterogeneousArrayLiterals.js
+++ b/tests/baselines/reference/heterogeneousArrayLiterals.js
@@ -136,8 +136,7 @@ function foo4<T extends Base, U extends Base>(t: T, u: U) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = [1, '']; // {}[]
 var b = [1, null]; // number[]
diff --git a/tests/baselines/reference/ifDoWhileStatements.js b/tests/baselines/reference/ifDoWhileStatements.js
index d389f70570..020d3f053d 100644
--- a/tests/baselines/reference/ifDoWhileStatements.js
+++ b/tests/baselines/reference/ifDoWhileStatements.js
@@ -166,8 +166,7 @@ do { }while(fn)
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/illegalSuperCallsInConstructor.js b/tests/baselines/reference/illegalSuperCallsInConstructor.js
index 57a382fe62..c3a5247374 100644
--- a/tests/baselines/reference/illegalSuperCallsInConstructor.js
+++ b/tests/baselines/reference/illegalSuperCallsInConstructor.js
@@ -24,8 +24,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/implementClausePrecedingExtends.js b/tests/baselines/reference/implementClausePrecedingExtends.js
index 7501c231dc..a929c2fb96 100644
--- a/tests/baselines/reference/implementClausePrecedingExtends.js
+++ b/tests/baselines/reference/implementClausePrecedingExtends.js
@@ -6,8 +6,7 @@ class D implements C extends C { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/implementingAnInterfaceExtendingClassWithPrivates2.js b/tests/baselines/reference/implementingAnInterfaceExtendingClassWithPrivates2.js
index 3d80d34485..cfa5ccf415 100644
--- a/tests/baselines/reference/implementingAnInterfaceExtendingClassWithPrivates2.js
+++ b/tests/baselines/reference/implementingAnInterfaceExtendingClassWithPrivates2.js
@@ -89,8 +89,7 @@ module M2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/implementingAnInterfaceExtendingClassWithProtecteds.js b/tests/baselines/reference/implementingAnInterfaceExtendingClassWithProtecteds.js
index 1fa40bf7aa..39f3042432 100644
--- a/tests/baselines/reference/implementingAnInterfaceExtendingClassWithProtecteds.js
+++ b/tests/baselines/reference/implementingAnInterfaceExtendingClassWithProtecteds.js
@@ -45,8 +45,7 @@ class Bar8 extends Foo implements I {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/importAsBaseClass.js b/tests/baselines/reference/importAsBaseClass.js
index 24f7e0477d..bcd8a5ce16 100644
--- a/tests/baselines/reference/importAsBaseClass.js
+++ b/tests/baselines/reference/importAsBaseClass.js
@@ -22,8 +22,7 @@ exports.Greeter = Greeter;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Hello = (function (_super) {
     __extends(Hello, _super);
diff --git a/tests/baselines/reference/importShadowsGlobalName.js b/tests/baselines/reference/importShadowsGlobalName.js
index 6db46eb41b..fe37e938a5 100644
--- a/tests/baselines/reference/importShadowsGlobalName.js
+++ b/tests/baselines/reference/importShadowsGlobalName.js
@@ -23,8 +23,7 @@ define(["require", "exports"], function (require, exports) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 define(["require", "exports", 'Foo'], function (require, exports, Error) {
     var Bar = (function (_super) {
diff --git a/tests/baselines/reference/importUsedInExtendsList1.js b/tests/baselines/reference/importUsedInExtendsList1.js
index 3e07ee084f..e86b1a4145 100644
--- a/tests/baselines/reference/importUsedInExtendsList1.js
+++ b/tests/baselines/reference/importUsedInExtendsList1.js
@@ -22,8 +22,7 @@ exports.Super = Super;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 ///<reference path='importUsedInExtendsList1_require.ts'/>
 var foo = require('importUsedInExtendsList1_require');
diff --git a/tests/baselines/reference/indexerConstraints2.js b/tests/baselines/reference/indexerConstraints2.js
index 7d3966688d..7e662bc66c 100644
--- a/tests/baselines/reference/indexerConstraints2.js
+++ b/tests/baselines/reference/indexerConstraints2.js
@@ -32,8 +32,7 @@ class K extends J {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/indirectSelfReference.js b/tests/baselines/reference/indirectSelfReference.js
index 3652d2962d..bd838ed881 100644
--- a/tests/baselines/reference/indirectSelfReference.js
+++ b/tests/baselines/reference/indirectSelfReference.js
@@ -6,8 +6,7 @@ class b extends a{ }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function (_super) {
     __extends(a, _super);
diff --git a/tests/baselines/reference/indirectSelfReferenceGeneric.js b/tests/baselines/reference/indirectSelfReferenceGeneric.js
index 079a37dc20..c9b4478ec1 100644
--- a/tests/baselines/reference/indirectSelfReferenceGeneric.js
+++ b/tests/baselines/reference/indirectSelfReferenceGeneric.js
@@ -6,8 +6,7 @@ class b<T> extends a<T> { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function (_super) {
     __extends(a, _super);
diff --git a/tests/baselines/reference/infinitelyExpandingTypesNonGenericBase.js b/tests/baselines/reference/infinitelyExpandingTypesNonGenericBase.js
index 71390b03c8..f057b649cb 100644
--- a/tests/baselines/reference/infinitelyExpandingTypesNonGenericBase.js
+++ b/tests/baselines/reference/infinitelyExpandingTypesNonGenericBase.js
@@ -28,8 +28,7 @@ o(A);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Functionality = (function () {
     function Functionality() {
diff --git a/tests/baselines/reference/inheritFromGenericTypeParameter.js b/tests/baselines/reference/inheritFromGenericTypeParameter.js
index ccf445a26b..ec6be00785 100644
--- a/tests/baselines/reference/inheritFromGenericTypeParameter.js
+++ b/tests/baselines/reference/inheritFromGenericTypeParameter.js
@@ -6,8 +6,7 @@ interface I<T> extends T { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/inheritSameNamePrivatePropertiesFromSameOrigin.js b/tests/baselines/reference/inheritSameNamePrivatePropertiesFromSameOrigin.js
index 850741c366..93494c7256 100644
--- a/tests/baselines/reference/inheritSameNamePrivatePropertiesFromSameOrigin.js
+++ b/tests/baselines/reference/inheritSameNamePrivatePropertiesFromSameOrigin.js
@@ -14,8 +14,7 @@ interface A extends C, C2 { // ok
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B = (function () {
     function B() {
diff --git a/tests/baselines/reference/inheritance.js b/tests/baselines/reference/inheritance.js
index f2b5be9335..b581ae894a 100644
--- a/tests/baselines/reference/inheritance.js
+++ b/tests/baselines/reference/inheritance.js
@@ -38,8 +38,7 @@ class Baad extends Good {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B1 = (function () {
     function B1() {
diff --git a/tests/baselines/reference/inheritance1.js b/tests/baselines/reference/inheritance1.js
index e0d4fa974c..aa7775b990 100644
--- a/tests/baselines/reference/inheritance1.js
+++ b/tests/baselines/reference/inheritance1.js
@@ -65,8 +65,7 @@ l1 = c;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Control = (function () {
     function Control() {
diff --git a/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollision.js b/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollision.js
index 0f016233ef..927ae96904 100644
--- a/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollision.js
+++ b/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollision.js
@@ -14,8 +14,7 @@ class C extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollisionWithPublicMember.js b/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollisionWithPublicMember.js
index 596982a479..05d8dc2a54 100644
--- a/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollisionWithPublicMember.js
+++ b/tests/baselines/reference/inheritanceGrandParentPrivateMemberCollisionWithPublicMember.js
@@ -14,8 +14,7 @@ class C extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/inheritanceGrandParentPublicMemberCollisionWithPrivateMember.js b/tests/baselines/reference/inheritanceGrandParentPublicMemberCollisionWithPrivateMember.js
index ec8ae03b3e..ddd87251f9 100644
--- a/tests/baselines/reference/inheritanceGrandParentPublicMemberCollisionWithPrivateMember.js
+++ b/tests/baselines/reference/inheritanceGrandParentPublicMemberCollisionWithPrivateMember.js
@@ -14,8 +14,7 @@ class C extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/inheritanceMemberAccessorOverridingAccessor.js b/tests/baselines/reference/inheritanceMemberAccessorOverridingAccessor.js
index 2da2bcbe6f..eaf34df921 100644
--- a/tests/baselines/reference/inheritanceMemberAccessorOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceMemberAccessorOverridingAccessor.js
@@ -21,8 +21,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceMemberAccessorOverridingMethod.js b/tests/baselines/reference/inheritanceMemberAccessorOverridingMethod.js
index 8b58a7f2b3..cd79d8c696 100644
--- a/tests/baselines/reference/inheritanceMemberAccessorOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceMemberAccessorOverridingMethod.js
@@ -18,8 +18,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceMemberAccessorOverridingProperty.js b/tests/baselines/reference/inheritanceMemberAccessorOverridingProperty.js
index 1864e62b23..18c1ab3395 100644
--- a/tests/baselines/reference/inheritanceMemberAccessorOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceMemberAccessorOverridingProperty.js
@@ -16,8 +16,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceMemberFuncOverridingAccessor.js b/tests/baselines/reference/inheritanceMemberFuncOverridingAccessor.js
index 0b24db92a3..5c25425171 100644
--- a/tests/baselines/reference/inheritanceMemberFuncOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceMemberFuncOverridingAccessor.js
@@ -18,8 +18,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceMemberFuncOverridingMethod.js b/tests/baselines/reference/inheritanceMemberFuncOverridingMethod.js
index bf1186a5cd..e2d3d9551c 100644
--- a/tests/baselines/reference/inheritanceMemberFuncOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceMemberFuncOverridingMethod.js
@@ -15,8 +15,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceMemberFuncOverridingProperty.js b/tests/baselines/reference/inheritanceMemberFuncOverridingProperty.js
index 2ecf7edb0e..b1d64aeb2c 100644
--- a/tests/baselines/reference/inheritanceMemberFuncOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceMemberFuncOverridingProperty.js
@@ -13,8 +13,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceMemberPropertyOverridingAccessor.js b/tests/baselines/reference/inheritanceMemberPropertyOverridingAccessor.js
index 512ca023de..bfa5d3fb80 100644
--- a/tests/baselines/reference/inheritanceMemberPropertyOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceMemberPropertyOverridingAccessor.js
@@ -17,8 +17,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceMemberPropertyOverridingMethod.js b/tests/baselines/reference/inheritanceMemberPropertyOverridingMethod.js
index 975727031e..d84f487963 100644
--- a/tests/baselines/reference/inheritanceMemberPropertyOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceMemberPropertyOverridingMethod.js
@@ -13,8 +13,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceMemberPropertyOverridingProperty.js b/tests/baselines/reference/inheritanceMemberPropertyOverridingProperty.js
index b924932e0b..8677d50227 100644
--- a/tests/baselines/reference/inheritanceMemberPropertyOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceMemberPropertyOverridingProperty.js
@@ -11,8 +11,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceOfGenericConstructorMethod1.js b/tests/baselines/reference/inheritanceOfGenericConstructorMethod1.js
index d62c62410b..73d3b4aa6c 100644
--- a/tests/baselines/reference/inheritanceOfGenericConstructorMethod1.js
+++ b/tests/baselines/reference/inheritanceOfGenericConstructorMethod1.js
@@ -11,8 +11,7 @@ var b3 = new B<Date>(); // error, could not select overload for 'new' expression
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/inheritanceOfGenericConstructorMethod2.js b/tests/baselines/reference/inheritanceOfGenericConstructorMethod2.js
index c54f8b4d31..e7e6228392 100644
--- a/tests/baselines/reference/inheritanceOfGenericConstructorMethod2.js
+++ b/tests/baselines/reference/inheritanceOfGenericConstructorMethod2.js
@@ -18,8 +18,7 @@ var n3 = new N.D2(); // no error, D2<any>
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/inheritanceStaticAccessorOverridingAccessor.js b/tests/baselines/reference/inheritanceStaticAccessorOverridingAccessor.js
index 120efc11e2..32f1d20eda 100644
--- a/tests/baselines/reference/inheritanceStaticAccessorOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceStaticAccessorOverridingAccessor.js
@@ -21,8 +21,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticAccessorOverridingMethod.js b/tests/baselines/reference/inheritanceStaticAccessorOverridingMethod.js
index 7200f37f94..7a1a86ced1 100644
--- a/tests/baselines/reference/inheritanceStaticAccessorOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceStaticAccessorOverridingMethod.js
@@ -18,8 +18,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticAccessorOverridingProperty.js b/tests/baselines/reference/inheritanceStaticAccessorOverridingProperty.js
index 2fd5e18dab..8a142d41c5 100644
--- a/tests/baselines/reference/inheritanceStaticAccessorOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceStaticAccessorOverridingProperty.js
@@ -16,8 +16,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingAccessor.js b/tests/baselines/reference/inheritanceStaticFuncOverridingAccessor.js
index 812ac57bfe..7c08ec7649 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingAccessor.js
@@ -18,8 +18,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingAccessorOfFuncType.js b/tests/baselines/reference/inheritanceStaticFuncOverridingAccessorOfFuncType.js
index 224c0326a8..acde620c10 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingAccessorOfFuncType.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingAccessorOfFuncType.js
@@ -15,8 +15,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingMethod.js b/tests/baselines/reference/inheritanceStaticFuncOverridingMethod.js
index 375f07fd90..abd4d7c149 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingMethod.js
@@ -15,8 +15,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingProperty.js b/tests/baselines/reference/inheritanceStaticFuncOverridingProperty.js
index c4d3f7ca42..c2d095e552 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingProperty.js
@@ -13,8 +13,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticFuncOverridingPropertyOfFuncType.js b/tests/baselines/reference/inheritanceStaticFuncOverridingPropertyOfFuncType.js
index f9513f6858..979f0c3635 100644
--- a/tests/baselines/reference/inheritanceStaticFuncOverridingPropertyOfFuncType.js
+++ b/tests/baselines/reference/inheritanceStaticFuncOverridingPropertyOfFuncType.js
@@ -13,8 +13,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticFunctionOverridingInstanceProperty.js b/tests/baselines/reference/inheritanceStaticFunctionOverridingInstanceProperty.js
index f64615e8a7..5c6c0e06a6 100644
--- a/tests/baselines/reference/inheritanceStaticFunctionOverridingInstanceProperty.js
+++ b/tests/baselines/reference/inheritanceStaticFunctionOverridingInstanceProperty.js
@@ -13,8 +13,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticMembersCompatible.js b/tests/baselines/reference/inheritanceStaticMembersCompatible.js
index f1e288c57f..014d327618 100644
--- a/tests/baselines/reference/inheritanceStaticMembersCompatible.js
+++ b/tests/baselines/reference/inheritanceStaticMembersCompatible.js
@@ -11,8 +11,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticMembersIncompatible.js b/tests/baselines/reference/inheritanceStaticMembersIncompatible.js
index 66ad861253..a1728dc6dc 100644
--- a/tests/baselines/reference/inheritanceStaticMembersIncompatible.js
+++ b/tests/baselines/reference/inheritanceStaticMembersIncompatible.js
@@ -11,8 +11,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticPropertyOverridingAccessor.js b/tests/baselines/reference/inheritanceStaticPropertyOverridingAccessor.js
index 310f2127e7..b81b6cd1d7 100644
--- a/tests/baselines/reference/inheritanceStaticPropertyOverridingAccessor.js
+++ b/tests/baselines/reference/inheritanceStaticPropertyOverridingAccessor.js
@@ -15,8 +15,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticPropertyOverridingMethod.js b/tests/baselines/reference/inheritanceStaticPropertyOverridingMethod.js
index 3e8a444d77..9afa969af6 100644
--- a/tests/baselines/reference/inheritanceStaticPropertyOverridingMethod.js
+++ b/tests/baselines/reference/inheritanceStaticPropertyOverridingMethod.js
@@ -13,8 +13,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritanceStaticPropertyOverridingProperty.js b/tests/baselines/reference/inheritanceStaticPropertyOverridingProperty.js
index 088cfa9b1f..fcecca6277 100644
--- a/tests/baselines/reference/inheritanceStaticPropertyOverridingProperty.js
+++ b/tests/baselines/reference/inheritanceStaticPropertyOverridingProperty.js
@@ -11,8 +11,7 @@ class b extends a {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = (function () {
     function a() {
diff --git a/tests/baselines/reference/inheritedConstructorWithRestParams.js b/tests/baselines/reference/inheritedConstructorWithRestParams.js
index 45f4fe7253..a0bb2ed8dc 100644
--- a/tests/baselines/reference/inheritedConstructorWithRestParams.js
+++ b/tests/baselines/reference/inheritedConstructorWithRestParams.js
@@ -18,8 +18,7 @@ new Derived(3);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/inheritedConstructorWithRestParams2.js b/tests/baselines/reference/inheritedConstructorWithRestParams2.js
index eeb0413d1e..9b87465233 100644
--- a/tests/baselines/reference/inheritedConstructorWithRestParams2.js
+++ b/tests/baselines/reference/inheritedConstructorWithRestParams2.js
@@ -38,8 +38,7 @@ new Derived("", 3, "", "");
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var IBaseBase = (function () {
     function IBaseBase(x) {
diff --git a/tests/baselines/reference/inheritedModuleMembersForClodule.js b/tests/baselines/reference/inheritedModuleMembersForClodule.js
index 75a2f13fed..50f41af2c0 100644
--- a/tests/baselines/reference/inheritedModuleMembersForClodule.js
+++ b/tests/baselines/reference/inheritedModuleMembersForClodule.js
@@ -25,8 +25,7 @@ class E extends D {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/instancePropertiesInheritedIntoClassType.js b/tests/baselines/reference/instancePropertiesInheritedIntoClassType.js
index 9e8e6d26b3..548cb77b87 100644
--- a/tests/baselines/reference/instancePropertiesInheritedIntoClassType.js
+++ b/tests/baselines/reference/instancePropertiesInheritedIntoClassType.js
@@ -46,8 +46,7 @@ module Generic {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var NonGeneric;
 (function (NonGeneric) {
diff --git a/tests/baselines/reference/instanceSubtypeCheck2.js b/tests/baselines/reference/instanceSubtypeCheck2.js
index e02a2b2afa..59043b29b4 100644
--- a/tests/baselines/reference/instanceSubtypeCheck2.js
+++ b/tests/baselines/reference/instanceSubtypeCheck2.js
@@ -11,8 +11,7 @@ class C2<T> extends C1<T> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1() {
diff --git a/tests/baselines/reference/instantiatedReturnTypeContravariance.js b/tests/baselines/reference/instantiatedReturnTypeContravariance.js
index 678f324797..2484816fe3 100644
--- a/tests/baselines/reference/instantiatedReturnTypeContravariance.js
+++ b/tests/baselines/reference/instantiatedReturnTypeContravariance.js
@@ -34,8 +34,7 @@ return null;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var c = (function () {
     function c() {
diff --git a/tests/baselines/reference/interfaceExtendsClass1.js b/tests/baselines/reference/interfaceExtendsClass1.js
index 5e72b36ef3..2fbe01bdf6 100644
--- a/tests/baselines/reference/interfaceExtendsClass1.js
+++ b/tests/baselines/reference/interfaceExtendsClass1.js
@@ -22,8 +22,7 @@ class Location {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Control = (function () {
     function Control() {
diff --git a/tests/baselines/reference/interfaceExtendsClassWithPrivate1.js b/tests/baselines/reference/interfaceExtendsClassWithPrivate1.js
index dac502b9ca..9a6e92c3e2 100644
--- a/tests/baselines/reference/interfaceExtendsClassWithPrivate1.js
+++ b/tests/baselines/reference/interfaceExtendsClassWithPrivate1.js
@@ -31,8 +31,7 @@ d = c; // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/interfaceExtendsClassWithPrivate2.js b/tests/baselines/reference/interfaceExtendsClassWithPrivate2.js
index c6a11c1d3a..44738036f9 100644
--- a/tests/baselines/reference/interfaceExtendsClassWithPrivate2.js
+++ b/tests/baselines/reference/interfaceExtendsClassWithPrivate2.js
@@ -27,8 +27,7 @@ class D2 extends C implements I { // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/interfaceImplementation8.js b/tests/baselines/reference/interfaceImplementation8.js
index 64b4c45382..cb6eaa1245 100644
--- a/tests/baselines/reference/interfaceImplementation8.js
+++ b/tests/baselines/reference/interfaceImplementation8.js
@@ -44,8 +44,7 @@ class C8 extends C7 implements i2{
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1() {
diff --git a/tests/baselines/reference/invalidModuleWithStatementsOfEveryKind.js b/tests/baselines/reference/invalidModuleWithStatementsOfEveryKind.js
index 4b3ab1b6d8..0b662b56f0 100644
--- a/tests/baselines/reference/invalidModuleWithStatementsOfEveryKind.js
+++ b/tests/baselines/reference/invalidModuleWithStatementsOfEveryKind.js
@@ -83,8 +83,7 @@ module YYY4 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Y;
 (function (Y) {
diff --git a/tests/baselines/reference/invalidMultipleVariableDeclarations.js b/tests/baselines/reference/invalidMultipleVariableDeclarations.js
index 31d0e44c91..b239a3dc1d 100644
--- a/tests/baselines/reference/invalidMultipleVariableDeclarations.js
+++ b/tests/baselines/reference/invalidMultipleVariableDeclarations.js
@@ -57,8 +57,7 @@ var m = M.A;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/invalidReturnStatements.js b/tests/baselines/reference/invalidReturnStatements.js
index 50977334f4..5fbe8c4dc3 100644
--- a/tests/baselines/reference/invalidReturnStatements.js
+++ b/tests/baselines/reference/invalidReturnStatements.js
@@ -24,8 +24,7 @@ function fn11(): D { return new C(); }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // all the following should be error
 function fn1() { }
diff --git a/tests/baselines/reference/isolatedModulesImportExportElision.js b/tests/baselines/reference/isolatedModulesImportExportElision.js
index ca3eee0ac2..8cb65747e6 100644
--- a/tests/baselines/reference/isolatedModulesImportExportElision.js
+++ b/tests/baselines/reference/isolatedModulesImportExportElision.js
@@ -17,8 +17,7 @@ export var z = x;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var module_1 = require("module");
 var module_2 = require("module");
diff --git a/tests/baselines/reference/lambdaArgCrash.js b/tests/baselines/reference/lambdaArgCrash.js
index 0f71ae803d..5616b5d525 100644
--- a/tests/baselines/reference/lambdaArgCrash.js
+++ b/tests/baselines/reference/lambdaArgCrash.js
@@ -38,8 +38,7 @@ class ItemSetEvent extends Event {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Event = (function () {
     function Event() {
diff --git a/tests/baselines/reference/lift.js b/tests/baselines/reference/lift.js
index eaaf94e702..a832b34641 100644
--- a/tests/baselines/reference/lift.js
+++ b/tests/baselines/reference/lift.js
@@ -21,8 +21,7 @@ class C extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B = (function () {
     function B(y) {
diff --git a/tests/baselines/reference/localTypes1.js b/tests/baselines/reference/localTypes1.js
index 09fa9c04f3..00c65db2c9 100644
--- a/tests/baselines/reference/localTypes1.js
+++ b/tests/baselines/reference/localTypes1.js
@@ -145,8 +145,7 @@ function f6() {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function f1() {
     var E;
diff --git a/tests/baselines/reference/m7Bugs.js b/tests/baselines/reference/m7Bugs.js
index 72829316fb..86b5aa96c7 100644
--- a/tests/baselines/reference/m7Bugs.js
+++ b/tests/baselines/reference/m7Bugs.js
@@ -30,8 +30,7 @@ var y3: C1 = <C1> {};
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var s = ({});
 var x = {};
diff --git a/tests/baselines/reference/mergedInterfacesWithInheritedPrivates2.js b/tests/baselines/reference/mergedInterfacesWithInheritedPrivates2.js
index 389bbfa63d..26cd3c8bf7 100644
--- a/tests/baselines/reference/mergedInterfacesWithInheritedPrivates2.js
+++ b/tests/baselines/reference/mergedInterfacesWithInheritedPrivates2.js
@@ -35,8 +35,7 @@ var r2 = a.w; // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/mergedInterfacesWithInheritedPrivates3.js b/tests/baselines/reference/mergedInterfacesWithInheritedPrivates3.js
index d088aab3d3..530595d54f 100644
--- a/tests/baselines/reference/mergedInterfacesWithInheritedPrivates3.js
+++ b/tests/baselines/reference/mergedInterfacesWithInheritedPrivates3.js
@@ -42,8 +42,7 @@ module M {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/moduleAsBaseType.js b/tests/baselines/reference/moduleAsBaseType.js
index c2246be879..7e2af06480 100644
--- a/tests/baselines/reference/moduleAsBaseType.js
+++ b/tests/baselines/reference/moduleAsBaseType.js
@@ -8,8 +8,7 @@ class C2 implements M { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/moduleImportedForTypeArgumentPosition.js b/tests/baselines/reference/moduleImportedForTypeArgumentPosition.js
index e8e08eed26..9b7449b95c 100644
--- a/tests/baselines/reference/moduleImportedForTypeArgumentPosition.js
+++ b/tests/baselines/reference/moduleImportedForTypeArgumentPosition.js
@@ -18,8 +18,7 @@ define(["require", "exports"], function (require, exports) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 define(["require", "exports"], function (require, exports) {
     var C1 = (function () {
diff --git a/tests/baselines/reference/moduleWithStatementsOfEveryKind.js b/tests/baselines/reference/moduleWithStatementsOfEveryKind.js
index 6c0f625f98..aeffc8d6e5 100644
--- a/tests/baselines/reference/moduleWithStatementsOfEveryKind.js
+++ b/tests/baselines/reference/moduleWithStatementsOfEveryKind.js
@@ -62,8 +62,7 @@ module Y {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A;
 (function (A_1) {
diff --git a/tests/baselines/reference/multipleInheritance.js b/tests/baselines/reference/multipleInheritance.js
index ea4a7156df..901838b584 100644
--- a/tests/baselines/reference/multipleInheritance.js
+++ b/tests/baselines/reference/multipleInheritance.js
@@ -42,8 +42,7 @@ class Baad extends Good {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B1 = (function () {
     function B1() {
diff --git a/tests/baselines/reference/mutuallyRecursiveGenericBaseTypes2.js b/tests/baselines/reference/mutuallyRecursiveGenericBaseTypes2.js
index 9b3d6f3129..09f4be0c4e 100644
--- a/tests/baselines/reference/mutuallyRecursiveGenericBaseTypes2.js
+++ b/tests/baselines/reference/mutuallyRecursiveGenericBaseTypes2.js
@@ -14,8 +14,7 @@ var test = new foo<string>();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var foo = (function () {
     function foo() {
diff --git a/tests/baselines/reference/nonGenericClassExtendingGenericClassWithAny.js b/tests/baselines/reference/nonGenericClassExtendingGenericClassWithAny.js
index b687162c15..7cdb702d6f 100644
--- a/tests/baselines/reference/nonGenericClassExtendingGenericClassWithAny.js
+++ b/tests/baselines/reference/nonGenericClassExtendingGenericClassWithAny.js
@@ -9,8 +9,7 @@ class Bar extends Foo<any> { } // Valid
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.js b/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.js
index fe1e476867..ade000d50b 100644
--- a/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.js
+++ b/tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.js
@@ -50,8 +50,7 @@ var b: { [x: number]: A } = {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/numericIndexerConstraint3.js b/tests/baselines/reference/numericIndexerConstraint3.js
index 724db29f55..dc3b6024ee 100644
--- a/tests/baselines/reference/numericIndexerConstraint3.js
+++ b/tests/baselines/reference/numericIndexerConstraint3.js
@@ -16,8 +16,7 @@ class C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/numericIndexerConstraint4.js b/tests/baselines/reference/numericIndexerConstraint4.js
index 404a9394bf..7509c64eac 100644
--- a/tests/baselines/reference/numericIndexerConstraint4.js
+++ b/tests/baselines/reference/numericIndexerConstraint4.js
@@ -15,8 +15,7 @@ var x: {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/numericIndexerTyping2.js b/tests/baselines/reference/numericIndexerTyping2.js
index c5e91e9dfc..2e3ba2ce74 100644
--- a/tests/baselines/reference/numericIndexerTyping2.js
+++ b/tests/baselines/reference/numericIndexerTyping2.js
@@ -16,8 +16,7 @@ var r2: string = i2[1]; // error: numeric indexer returns the type of the string
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var I = (function () {
     function I() {
diff --git a/tests/baselines/reference/objectCreationOfElementAccessExpression.js b/tests/baselines/reference/objectCreationOfElementAccessExpression.js
index 45d56a1d71..05457a559e 100644
--- a/tests/baselines/reference/objectCreationOfElementAccessExpression.js
+++ b/tests/baselines/reference/objectCreationOfElementAccessExpression.js
@@ -59,8 +59,7 @@ var foods2: MonsterFood[] = new PetFood[new IceCream('Mint chocolate chip') , Co
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Food = (function () {
     function Food(name) {
diff --git a/tests/baselines/reference/objectTypeHidingMembersOfExtendedObject.js b/tests/baselines/reference/objectTypeHidingMembersOfExtendedObject.js
index 339f6b23f6..5d30e0faec 100644
--- a/tests/baselines/reference/objectTypeHidingMembersOfExtendedObject.js
+++ b/tests/baselines/reference/objectTypeHidingMembersOfExtendedObject.js
@@ -58,8 +58,7 @@ var r4: void = b.valueOf();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.js b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.js
index 8f6d1706e4..e0f626ae08 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.js
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers1.js
@@ -127,8 +127,7 @@ function foo16(x: any) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.js b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.js
index 8f5b6449a8..f0417a7ca2 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.js
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers2.js
@@ -130,8 +130,7 @@ function foo16(x: any) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.js b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.js
index 2fc8c0c946..e147379055 100644
--- a/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.js
+++ b/tests/baselines/reference/objectTypesIdentityWithNumericIndexers3.js
@@ -127,8 +127,7 @@ function foo16(x: any) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/objectTypesIdentityWithPrivates.js b/tests/baselines/reference/objectTypesIdentityWithPrivates.js
index a68eba8c6a..bf4f80da15 100644
--- a/tests/baselines/reference/objectTypesIdentityWithPrivates.js
+++ b/tests/baselines/reference/objectTypesIdentityWithPrivates.js
@@ -125,8 +125,7 @@ function foo16(x: any) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/objectTypesIdentityWithPrivates2.js b/tests/baselines/reference/objectTypesIdentityWithPrivates2.js
index 92aac37ecd..c8cd12cff3 100644
--- a/tests/baselines/reference/objectTypesIdentityWithPrivates2.js
+++ b/tests/baselines/reference/objectTypesIdentityWithPrivates2.js
@@ -43,8 +43,7 @@ function foo6(x: any): any { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/objectTypesIdentityWithPrivates3.js b/tests/baselines/reference/objectTypesIdentityWithPrivates3.js
index c202f68489..a812a1fc4b 100644
--- a/tests/baselines/reference/objectTypesIdentityWithPrivates3.js
+++ b/tests/baselines/reference/objectTypesIdentityWithPrivates3.js
@@ -29,8 +29,7 @@ var c3: C3<T2>;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1() {
diff --git a/tests/baselines/reference/objectTypesIdentityWithStringIndexers.js b/tests/baselines/reference/objectTypesIdentityWithStringIndexers.js
index 98693b4e6e..9cf9e99cb4 100644
--- a/tests/baselines/reference/objectTypesIdentityWithStringIndexers.js
+++ b/tests/baselines/reference/objectTypesIdentityWithStringIndexers.js
@@ -127,8 +127,7 @@ function foo16(x: any) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.js b/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.js
index 7e9abbad7e..84f3d04e7b 100644
--- a/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.js
+++ b/tests/baselines/reference/objectTypesIdentityWithStringIndexers2.js
@@ -130,8 +130,7 @@ function foo16(x: any) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/optionalConstructorArgInSuper.js b/tests/baselines/reference/optionalConstructorArgInSuper.js
index 2ac23c39be..e8b65ea511 100644
--- a/tests/baselines/reference/optionalConstructorArgInSuper.js
+++ b/tests/baselines/reference/optionalConstructorArgInSuper.js
@@ -14,8 +14,7 @@ d2.foo();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(opt) {
diff --git a/tests/baselines/reference/optionalParamArgsTest.js b/tests/baselines/reference/optionalParamArgsTest.js
index 7538397566..414f474598 100644
--- a/tests/baselines/reference/optionalParamArgsTest.js
+++ b/tests/baselines/reference/optionalParamArgsTest.js
@@ -129,8 +129,7 @@ fnOpt2(1, [2, 3], [1], true);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // test basic configurations
 var C1 = (function () {
diff --git a/tests/baselines/reference/optionalParamInOverride.js b/tests/baselines/reference/optionalParamInOverride.js
index aa76f41644..4a72953bda 100644
--- a/tests/baselines/reference/optionalParamInOverride.js
+++ b/tests/baselines/reference/optionalParamInOverride.js
@@ -11,8 +11,7 @@ class Y extends Z {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Z = (function () {
     function Z() {
diff --git a/tests/baselines/reference/overload1.js b/tests/baselines/reference/overload1.js
index b308c0e8d8..af3aebde4e 100644
--- a/tests/baselines/reference/overload1.js
+++ b/tests/baselines/reference/overload1.js
@@ -43,8 +43,7 @@ var v=x.g;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var O;
 (function (O) {
diff --git a/tests/baselines/reference/overloadOnConstConstraintChecks1.js b/tests/baselines/reference/overloadOnConstConstraintChecks1.js
index 4588bef017..67aa365ee3 100644
--- a/tests/baselines/reference/overloadOnConstConstraintChecks1.js
+++ b/tests/baselines/reference/overloadOnConstConstraintChecks1.js
@@ -26,8 +26,7 @@ class D implements MyDoc {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/overloadOnConstConstraintChecks2.js b/tests/baselines/reference/overloadOnConstConstraintChecks2.js
index 709f7808ac..353680bb92 100644
--- a/tests/baselines/reference/overloadOnConstConstraintChecks2.js
+++ b/tests/baselines/reference/overloadOnConstConstraintChecks2.js
@@ -15,8 +15,7 @@ function foo(name: any): A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/overloadOnConstConstraintChecks3.js b/tests/baselines/reference/overloadOnConstConstraintChecks3.js
index 7104c44193..2debaa589f 100644
--- a/tests/baselines/reference/overloadOnConstConstraintChecks3.js
+++ b/tests/baselines/reference/overloadOnConstConstraintChecks3.js
@@ -16,8 +16,7 @@ function foo(name: any): A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/overloadOnConstConstraintChecks4.js b/tests/baselines/reference/overloadOnConstConstraintChecks4.js
index 4483b42a94..17ec377962 100644
--- a/tests/baselines/reference/overloadOnConstConstraintChecks4.js
+++ b/tests/baselines/reference/overloadOnConstConstraintChecks4.js
@@ -17,8 +17,7 @@ function foo(name: any): Z {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Z = (function () {
     function Z() {
diff --git a/tests/baselines/reference/overloadOnConstantsInvalidOverload1.js b/tests/baselines/reference/overloadOnConstantsInvalidOverload1.js
index efcad011ab..a8dfcde9ad 100644
--- a/tests/baselines/reference/overloadOnConstantsInvalidOverload1.js
+++ b/tests/baselines/reference/overloadOnConstantsInvalidOverload1.js
@@ -15,8 +15,7 @@ foo("HI");
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/overloadResolution.js b/tests/baselines/reference/overloadResolution.js
index d234ea4a69..287c5ccdb8 100644
--- a/tests/baselines/reference/overloadResolution.js
+++ b/tests/baselines/reference/overloadResolution.js
@@ -98,8 +98,7 @@ var s = fn5((n) => n.substr(0));
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var SomeBase = (function () {
     function SomeBase() {
diff --git a/tests/baselines/reference/overloadResolutionClassConstructors.js b/tests/baselines/reference/overloadResolutionClassConstructors.js
index fc7dbd9ceb..14306b7873 100644
--- a/tests/baselines/reference/overloadResolutionClassConstructors.js
+++ b/tests/baselines/reference/overloadResolutionClassConstructors.js
@@ -105,8 +105,7 @@ new fn5((n) => n.blah); // Error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var SomeBase = (function () {
     function SomeBase() {
diff --git a/tests/baselines/reference/overloadResolutionConstructors.js b/tests/baselines/reference/overloadResolutionConstructors.js
index b3c2b2ef76..788e6362f8 100644
--- a/tests/baselines/reference/overloadResolutionConstructors.js
+++ b/tests/baselines/reference/overloadResolutionConstructors.js
@@ -106,8 +106,7 @@ var s = new fn5((n) => n.substr(0));
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var SomeBase = (function () {
     function SomeBase() {
diff --git a/tests/baselines/reference/overloadingOnConstants1.js b/tests/baselines/reference/overloadingOnConstants1.js
index 4274841d60..bd08f70498 100644
--- a/tests/baselines/reference/overloadingOnConstants1.js
+++ b/tests/baselines/reference/overloadingOnConstants1.js
@@ -29,8 +29,7 @@ var htmlSpanElement2: Derived1 = d2.createElement("span");
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/overloadingOnConstants2.js b/tests/baselines/reference/overloadingOnConstants2.js
index 2414ec4eab..eaec0054f6 100644
--- a/tests/baselines/reference/overloadingOnConstants2.js
+++ b/tests/baselines/reference/overloadingOnConstants2.js
@@ -31,8 +31,7 @@ var f: C = bar("um", []); // C
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/overridingPrivateStaticMembers.js b/tests/baselines/reference/overridingPrivateStaticMembers.js
index 56ecfec66c..a155bb1b83 100644
--- a/tests/baselines/reference/overridingPrivateStaticMembers.js
+++ b/tests/baselines/reference/overridingPrivateStaticMembers.js
@@ -11,8 +11,7 @@ class Derived2 extends Base2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base2 = (function () {
     function Base2() {
diff --git a/tests/baselines/reference/parseErrorInHeritageClause1.js b/tests/baselines/reference/parseErrorInHeritageClause1.js
index 66facdeadf..b6640b6425 100644
--- a/tests/baselines/reference/parseErrorInHeritageClause1.js
+++ b/tests/baselines/reference/parseErrorInHeritageClause1.js
@@ -6,8 +6,7 @@ class C extends A # {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parser509630.js b/tests/baselines/reference/parser509630.js
index 20e00ea01e..6862eef4a9 100644
--- a/tests/baselines/reference/parser509630.js
+++ b/tests/baselines/reference/parser509630.js
@@ -10,8 +10,7 @@ class Any extends Type {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Type = (function () {
     function Type() {
diff --git a/tests/baselines/reference/parserAstSpans1.js b/tests/baselines/reference/parserAstSpans1.js
index ec88d11b0c..5de3cb8f9f 100644
--- a/tests/baselines/reference/parserAstSpans1.js
+++ b/tests/baselines/reference/parserAstSpans1.js
@@ -223,8 +223,7 @@ class c6 extends c5 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var c1 = (function () {
     function c1() {
diff --git a/tests/baselines/reference/parserClassDeclaration1.js b/tests/baselines/reference/parserClassDeclaration1.js
index 9ef865adb7..f430b8e644 100644
--- a/tests/baselines/reference/parserClassDeclaration1.js
+++ b/tests/baselines/reference/parserClassDeclaration1.js
@@ -6,8 +6,7 @@ class C extends A extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserClassDeclaration3.js b/tests/baselines/reference/parserClassDeclaration3.js
index 644c4fcb54..8ea681a668 100644
--- a/tests/baselines/reference/parserClassDeclaration3.js
+++ b/tests/baselines/reference/parserClassDeclaration3.js
@@ -6,8 +6,7 @@ class C implements A extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserClassDeclaration4.js b/tests/baselines/reference/parserClassDeclaration4.js
index d7cd9ca6ca..2bbbd134ed 100644
--- a/tests/baselines/reference/parserClassDeclaration4.js
+++ b/tests/baselines/reference/parserClassDeclaration4.js
@@ -6,8 +6,7 @@ class C extends A implements B extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserClassDeclaration5.js b/tests/baselines/reference/parserClassDeclaration5.js
index 4f75eb9666..146cbda956 100644
--- a/tests/baselines/reference/parserClassDeclaration5.js
+++ b/tests/baselines/reference/parserClassDeclaration5.js
@@ -6,8 +6,7 @@ class C extends A implements B implements C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserClassDeclaration6.js b/tests/baselines/reference/parserClassDeclaration6.js
index a653a7e404..0f65ad53f0 100644
--- a/tests/baselines/reference/parserClassDeclaration6.js
+++ b/tests/baselines/reference/parserClassDeclaration6.js
@@ -6,8 +6,7 @@ class C extends A, B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause2.js b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause2.js
index 43ebfa2bb0..3c2f96f54f 100644
--- a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause2.js
+++ b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause2.js
@@ -6,8 +6,7 @@ class C extends A, {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause4.js b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause4.js
index 732508b8d8..594c4575ea 100644
--- a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause4.js
+++ b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause4.js
@@ -6,8 +6,7 @@ class C extends A implements {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause5.js b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause5.js
index 58f4f4631d..3d2447e0b8 100644
--- a/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause5.js
+++ b/tests/baselines/reference/parserErrorRecovery_ExtendsOrImplementsClause5.js
@@ -6,8 +6,7 @@ class C extends A, implements B, {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserGenericsInTypeContexts1.js b/tests/baselines/reference/parserGenericsInTypeContexts1.js
index 5c2369e61c..9cea884bcf 100644
--- a/tests/baselines/reference/parserGenericsInTypeContexts1.js
+++ b/tests/baselines/reference/parserGenericsInTypeContexts1.js
@@ -21,8 +21,7 @@ function f2(): F<T> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserGenericsInTypeContexts2.js b/tests/baselines/reference/parserGenericsInTypeContexts2.js
index 487038e195..b5e5e010d5 100644
--- a/tests/baselines/reference/parserGenericsInTypeContexts2.js
+++ b/tests/baselines/reference/parserGenericsInTypeContexts2.js
@@ -21,8 +21,7 @@ function f2(): F<X<T>, Y<Z<T>>> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/parserRealSource10.js b/tests/baselines/reference/parserRealSource10.js
index 4c241abba0..f184db9173 100644
--- a/tests/baselines/reference/parserRealSource10.js
+++ b/tests/baselines/reference/parserRealSource10.js
@@ -461,8 +461,7 @@ module TypeScript {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 ///<reference path='typescript.ts' />
 var TypeScript;
diff --git a/tests/baselines/reference/parserRealSource11.js b/tests/baselines/reference/parserRealSource11.js
index c6a0806282..4091eb290d 100644
--- a/tests/baselines/reference/parserRealSource11.js
+++ b/tests/baselines/reference/parserRealSource11.js
@@ -2370,8 +2370,7 @@ module TypeScript {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 ///<reference path='typescript.ts' />
 var TypeScript;
diff --git a/tests/baselines/reference/parserharness.js b/tests/baselines/reference/parserharness.js
index 4e22c804ab..296aae05fa 100644
--- a/tests/baselines/reference/parserharness.js
+++ b/tests/baselines/reference/parserharness.js
@@ -2099,8 +2099,7 @@ module Harness {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 ///<reference path='..\compiler\io.ts'/>
 ///<reference path='..\compiler\typescript.ts'/>
diff --git a/tests/baselines/reference/primitiveMembers.js b/tests/baselines/reference/primitiveMembers.js
index a49d6f7ee1..60ae4b79de 100644
--- a/tests/baselines/reference/primitiveMembers.js
+++ b/tests/baselines/reference/primitiveMembers.js
@@ -35,8 +35,7 @@ class foo extends baz { public bar(){ return undefined}; }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x = 5;
 var r = /yo/;
diff --git a/tests/baselines/reference/privacyClass.js b/tests/baselines/reference/privacyClass.js
index 4d6d0a72e4..f632ea8b26 100644
--- a/tests/baselines/reference/privacyClass.js
+++ b/tests/baselines/reference/privacyClass.js
@@ -131,8 +131,7 @@ export class glo_C12_public extends glo_c_private implements  glo_i_private, glo
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var m1;
 (function (m1) {
diff --git a/tests/baselines/reference/privacyClassExtendsClauseDeclFile.js b/tests/baselines/reference/privacyClassExtendsClauseDeclFile.js
index 044c30f379..a3ddd38788 100644
--- a/tests/baselines/reference/privacyClassExtendsClauseDeclFile.js
+++ b/tests/baselines/reference/privacyClassExtendsClauseDeclFile.js
@@ -101,8 +101,7 @@ class publicClassExtendingPublicClassInGlobal extends publicClassInGlobal {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var publicModule;
 (function (publicModule) {
@@ -288,8 +287,7 @@ exports.publicClassExtendingFromPrivateModuleClass = publicClassExtendingFromPri
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var publicModuleInGlobal;
 (function (publicModuleInGlobal) {
diff --git a/tests/baselines/reference/privacyGloClass.js b/tests/baselines/reference/privacyGloClass.js
index 58877eae16..01eff31273 100644
--- a/tests/baselines/reference/privacyGloClass.js
+++ b/tests/baselines/reference/privacyGloClass.js
@@ -64,8 +64,7 @@ class glo_C11_public extends glo_c_public implements glo_i_public {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var m1;
 (function (m1) {
diff --git a/tests/baselines/reference/privateAccessInSubclass1.js b/tests/baselines/reference/privateAccessInSubclass1.js
index 7004a53595..b22af20af3 100644
--- a/tests/baselines/reference/privateAccessInSubclass1.js
+++ b/tests/baselines/reference/privateAccessInSubclass1.js
@@ -13,8 +13,7 @@ class D extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/privateInstanceMemberAccessibility.js b/tests/baselines/reference/privateInstanceMemberAccessibility.js
index 4158ef6a8f..ac2f44ee5d 100644
--- a/tests/baselines/reference/privateInstanceMemberAccessibility.js
+++ b/tests/baselines/reference/privateInstanceMemberAccessibility.js
@@ -17,8 +17,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/privateStaticMemberAccessibility.js b/tests/baselines/reference/privateStaticMemberAccessibility.js
index 013c606f82..0b9be3b69f 100644
--- a/tests/baselines/reference/privateStaticMemberAccessibility.js
+++ b/tests/baselines/reference/privateStaticMemberAccessibility.js
@@ -12,8 +12,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/privateStaticNotAccessibleInClodule2.js b/tests/baselines/reference/privateStaticNotAccessibleInClodule2.js
index 3db3a636c7..b67ca77dc2 100644
--- a/tests/baselines/reference/privateStaticNotAccessibleInClodule2.js
+++ b/tests/baselines/reference/privateStaticNotAccessibleInClodule2.js
@@ -19,8 +19,7 @@ module D {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/amd/testGlo.js b/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/amd/testGlo.js
index 1ce3452dbe..bab996e07a 100644
--- a/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/amd/testGlo.js
+++ b/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/amd/testGlo.js
@@ -1,8 +1,7 @@
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var m2;
 (function (m2) {
diff --git a/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/node/testGlo.js b/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/node/testGlo.js
index 1ce3452dbe..bab996e07a 100644
--- a/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/node/testGlo.js
+++ b/tests/baselines/reference/project/privacyCheckOnImportedModuleDeclarationsInsideModule/node/testGlo.js
@@ -1,8 +1,7 @@
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var m2;
 (function (m2) {
diff --git a/tests/baselines/reference/project/prologueEmit/amd/out.js b/tests/baselines/reference/project/prologueEmit/amd/out.js
index e621c38f98..fb0ca5dfac 100644
--- a/tests/baselines/reference/project/prologueEmit/amd/out.js
+++ b/tests/baselines/reference/project/prologueEmit/amd/out.js
@@ -4,8 +4,7 @@ var _this = this;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // class inheritance to ensure __extends is emitted
 var m;
diff --git a/tests/baselines/reference/project/prologueEmit/node/out.js b/tests/baselines/reference/project/prologueEmit/node/out.js
index e621c38f98..fb0ca5dfac 100644
--- a/tests/baselines/reference/project/prologueEmit/node/out.js
+++ b/tests/baselines/reference/project/prologueEmit/node/out.js
@@ -4,8 +4,7 @@ var _this = this;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // class inheritance to ensure __extends is emitted
 var m;
diff --git a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts
deleted file mode 100644
index d7b4c67d49..0000000000
--- a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-/// <reference path="li'b/class'A.d.ts" />
-declare class ClassC extends test.ClassA {
-}
diff --git a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.js b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.js
index b1f4dd64ef..bdf2edefcb 100644
--- a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.js
+++ b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.js
@@ -2,8 +2,7 @@
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var ClassC = (function (_super) {
     __extends(ClassC, _super);
diff --git a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.d.ts b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.d.ts
deleted file mode 100644
index d7b4c67d49..0000000000
--- a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.d.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-/// <reference path="li'b/class'A.d.ts" />
-declare class ClassC extends test.ClassA {
-}
diff --git a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.js b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.js
index b1f4dd64ef..bdf2edefcb 100644
--- a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.js
+++ b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.js
@@ -2,8 +2,7 @@
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var ClassC = (function (_super) {
     __extends(ClassC, _super);
diff --git a/tests/baselines/reference/propertiesAndIndexers.js b/tests/baselines/reference/propertiesAndIndexers.js
index f67a9d8924..b7a39ae233 100644
--- a/tests/baselines/reference/propertiesAndIndexers.js
+++ b/tests/baselines/reference/propertiesAndIndexers.js
@@ -55,8 +55,7 @@ var c: {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var P = (function () {
     function P() {
diff --git a/tests/baselines/reference/propertyAccess.js b/tests/baselines/reference/propertyAccess.js
index 1e6ef5c1d6..ed004b332c 100644
--- a/tests/baselines/reference/propertyAccess.js
+++ b/tests/baselines/reference/propertyAccess.js
@@ -154,8 +154,7 @@ var x3: A;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints2.js b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints2.js
index dc4c30d916..35c279ba0e 100644
--- a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints2.js
+++ b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints2.js
@@ -86,8 +86,7 @@ var r4 = b.foo(aB, aB); // no inferences for T so constraint isn't satisfied, er
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints3.js b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints3.js
index 7e935609e3..24c3fc5050 100644
--- a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints3.js
+++ b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints3.js
@@ -61,8 +61,7 @@ var r4 = b.foo(new B()); // valid call to an invalid function
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints5.js b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints5.js
index f871ce553b..37b8240b9a 100644
--- a/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints5.js
+++ b/tests/baselines/reference/propertyAccessOnTypeParameterWithConstraints5.js
@@ -48,8 +48,7 @@ var r4 = b.foo(new B()); // error after constraints above made illegal, doesn't
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass.js b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass.js
index 45f001c65f..ce7bc5d0b4 100644
--- a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass.js
+++ b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass.js
@@ -24,8 +24,7 @@ class C extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B = (function () {
     function B() {
diff --git a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass2.js b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass2.js
index 10276f8ac8..e47e7e5a7d 100644
--- a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass2.js
+++ b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass2.js
@@ -98,8 +98,7 @@ d4.x;                   // Error, neither within their declaring class nor class
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass3.js b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass3.js
index 1a5b748991..0140e61406 100644
--- a/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass3.js
+++ b/tests/baselines/reference/protectedClassPropertyAccessibleWithinSubclass3.js
@@ -17,8 +17,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/protectedInstanceMemberAccessibility.js b/tests/baselines/reference/protectedInstanceMemberAccessibility.js
index 7560c5c89c..ff4ae95224 100644
--- a/tests/baselines/reference/protectedInstanceMemberAccessibility.js
+++ b/tests/baselines/reference/protectedInstanceMemberAccessibility.js
@@ -48,8 +48,7 @@ class C extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/protectedMembers.js b/tests/baselines/reference/protectedMembers.js
index 33b6e2ebde..f86818b6e6 100644
--- a/tests/baselines/reference/protectedMembers.js
+++ b/tests/baselines/reference/protectedMembers.js
@@ -120,8 +120,7 @@ class B3 extends A3 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // Class with protected members
 var C1 = (function () {
diff --git a/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass.js b/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass.js
index 1bd102694d..9edd43ad52 100644
--- a/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass.js
+++ b/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass.js
@@ -47,8 +47,7 @@ Derived3.x;     // Error, neither within their declaring class nor classes deriv
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass2.js b/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass2.js
index c82c67b700..5a8b07df37 100644
--- a/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass2.js
+++ b/tests/baselines/reference/protectedStaticClassPropertyAccessibleWithinSubclass2.js
@@ -25,8 +25,7 @@ class Derived2 extends Derived1 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/qualifiedName_entity-name-resolution-does-not-affect-class-heritage.js b/tests/baselines/reference/qualifiedName_entity-name-resolution-does-not-affect-class-heritage.js
index 8b071cb6b5..b0079c2f45 100644
--- a/tests/baselines/reference/qualifiedName_entity-name-resolution-does-not-affect-class-heritage.js
+++ b/tests/baselines/reference/qualifiedName_entity-name-resolution-does-not-affect-class-heritage.js
@@ -10,8 +10,7 @@ class Beta extends Alpha.x {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Alpha;
 (function (Alpha) {
diff --git a/tests/baselines/reference/recursiveBaseCheck3.js b/tests/baselines/reference/recursiveBaseCheck3.js
index 6c1cd91877..aeb0d70240 100644
--- a/tests/baselines/reference/recursiveBaseCheck3.js
+++ b/tests/baselines/reference/recursiveBaseCheck3.js
@@ -8,8 +8,7 @@ class C<T> extends A<T> { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function (_super) {
     __extends(A, _super);
diff --git a/tests/baselines/reference/recursiveBaseCheck4.js b/tests/baselines/reference/recursiveBaseCheck4.js
index 1abb673126..2e4a745a70 100644
--- a/tests/baselines/reference/recursiveBaseCheck4.js
+++ b/tests/baselines/reference/recursiveBaseCheck4.js
@@ -6,8 +6,7 @@ class M<T> extends M<string> { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M = (function (_super) {
     __extends(M, _super);
diff --git a/tests/baselines/reference/recursiveBaseCheck6.js b/tests/baselines/reference/recursiveBaseCheck6.js
index 7fb9b44465..13b4944e96 100644
--- a/tests/baselines/reference/recursiveBaseCheck6.js
+++ b/tests/baselines/reference/recursiveBaseCheck6.js
@@ -6,8 +6,7 @@ class S18<A> extends S18<{ S19: A; }>{ }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var S18 = (function (_super) {
     __extends(S18, _super);
diff --git a/tests/baselines/reference/recursiveBaseConstructorCreation1.js b/tests/baselines/reference/recursiveBaseConstructorCreation1.js
index d0fc83b30f..d14a78ed90 100644
--- a/tests/baselines/reference/recursiveBaseConstructorCreation1.js
+++ b/tests/baselines/reference/recursiveBaseConstructorCreation1.js
@@ -10,8 +10,7 @@ var x = new C2(); // Valid
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1() {
diff --git a/tests/baselines/reference/recursiveClassInstantiationsWithDefaultConstructors.js b/tests/baselines/reference/recursiveClassInstantiationsWithDefaultConstructors.js
index 214c543b83..224c13e776 100644
--- a/tests/baselines/reference/recursiveClassInstantiationsWithDefaultConstructors.js
+++ b/tests/baselines/reference/recursiveClassInstantiationsWithDefaultConstructors.js
@@ -13,8 +13,7 @@ export class MemberNameArray extends MemberName {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var a = new TypeScript2.MemberNameArray();
 var TypeScript2;
diff --git a/tests/baselines/reference/recursiveClassReferenceTest.js b/tests/baselines/reference/recursiveClassReferenceTest.js
index e9339fec4d..0e884b94e8 100644
--- a/tests/baselines/reference/recursiveClassReferenceTest.js
+++ b/tests/baselines/reference/recursiveClassReferenceTest.js
@@ -108,8 +108,7 @@ module Sample.Thing.Languages.PlainText {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Sample;
 (function (Sample) {
diff --git a/tests/baselines/reference/recursiveClassReferenceTest.js.map b/tests/baselines/reference/recursiveClassReferenceTest.js.map
index 5573bdd8de..734906688f 100644
--- a/tests/baselines/reference/recursiveClassReferenceTest.js.map
+++ b/tests/baselines/reference/recursiveClassReferenceTest.js.map
@@ -1,2 +1,2 @@
 //// [recursiveClassReferenceTest.js.map]
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\ No newline at end of file
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diff --git a/tests/baselines/reference/recursiveClassReferenceTest.sourcemap.txt b/tests/baselines/reference/recursiveClassReferenceTest.sourcemap.txt
index 67031d420e..8f45e0ea71 100644
--- a/tests/baselines/reference/recursiveClassReferenceTest.sourcemap.txt
+++ b/tests/baselines/reference/recursiveClassReferenceTest.sourcemap.txt
@@ -29,8 +29,7 @@ sourceFile:recursiveClassReferenceTest.ts
 >>>var __extends = (this && this.__extends) || function (d, b) {
 >>>    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
 >>>    function __() { this.constructor = d; }
->>>    __.prototype = b.prototype;
->>>    d.prototype = new __();
+>>>    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 >>>};
 >>>var Sample;
 1 >
@@ -82,10 +81,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >          		}
   >          	}
   >          }
-1 >Emitted(9, 1) Source(32, 1) + SourceIndex(0)
-2 >Emitted(9, 5) Source(32, 8) + SourceIndex(0)
-3 >Emitted(9, 11) Source(32, 14) + SourceIndex(0)
-4 >Emitted(9, 12) Source(42, 2) + SourceIndex(0)
+1 >Emitted(8, 1) Source(32, 1) + SourceIndex(0)
+2 >Emitted(8, 5) Source(32, 8) + SourceIndex(0)
+3 >Emitted(8, 11) Source(32, 14) + SourceIndex(0)
+4 >Emitted(8, 12) Source(42, 2) + SourceIndex(0)
 ---
 >>>(function (Sample) {
 1->
@@ -94,9 +93,9 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
 2 >module 
 3 >           Sample
-1->Emitted(10, 1) Source(32, 1) + SourceIndex(0)
-2 >Emitted(10, 12) Source(32, 8) + SourceIndex(0)
-3 >Emitted(10, 18) Source(32, 14) + SourceIndex(0)
+1->Emitted(9, 1) Source(32, 1) + SourceIndex(0)
+2 >Emitted(9, 12) Source(32, 8) + SourceIndex(0)
+3 >Emitted(9, 18) Source(32, 14) + SourceIndex(0)
 ---
 >>>    var Actions;
 1 >^^^^
@@ -118,10 +117,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >               		}
   >               	}
   >               }
-1 >Emitted(11, 5) Source(32, 15) + SourceIndex(0) name (Sample)
-2 >Emitted(11, 9) Source(32, 15) + SourceIndex(0) name (Sample)
-3 >Emitted(11, 16) Source(32, 22) + SourceIndex(0) name (Sample)
-4 >Emitted(11, 17) Source(42, 2) + SourceIndex(0) name (Sample)
+1 >Emitted(10, 5) Source(32, 15) + SourceIndex(0) name (Sample)
+2 >Emitted(10, 9) Source(32, 15) + SourceIndex(0) name (Sample)
+3 >Emitted(10, 16) Source(32, 22) + SourceIndex(0) name (Sample)
+4 >Emitted(10, 17) Source(42, 2) + SourceIndex(0) name (Sample)
 ---
 >>>    (function (Actions) {
 1->^^^^
@@ -130,9 +129,9 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
 2 >    
 3 >               Actions
-1->Emitted(12, 5) Source(32, 15) + SourceIndex(0) name (Sample)
-2 >Emitted(12, 16) Source(32, 15) + SourceIndex(0) name (Sample)
-3 >Emitted(12, 23) Source(32, 22) + SourceIndex(0) name (Sample)
+1->Emitted(11, 5) Source(32, 15) + SourceIndex(0) name (Sample)
+2 >Emitted(11, 16) Source(32, 15) + SourceIndex(0) name (Sample)
+3 >Emitted(11, 23) Source(32, 22) + SourceIndex(0) name (Sample)
 ---
 >>>        var Thing;
 1 >^^^^^^^^
@@ -154,10 +153,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                 		}
   >                 	}
   >                 }
-1 >Emitted(13, 9) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
-2 >Emitted(13, 13) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
-3 >Emitted(13, 18) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
-4 >Emitted(13, 19) Source(42, 2) + SourceIndex(0) name (Sample.Actions)
+1 >Emitted(12, 9) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
+2 >Emitted(12, 13) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
+3 >Emitted(12, 18) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
+4 >Emitted(12, 19) Source(42, 2) + SourceIndex(0) name (Sample.Actions)
 ---
 >>>        (function (Thing_1) {
 1->^^^^^^^^
@@ -166,9 +165,9 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
 2 >        
 3 >                   Thing
-1->Emitted(14, 9) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
-2 >Emitted(14, 20) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
-3 >Emitted(14, 27) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
+1->Emitted(13, 9) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
+2 >Emitted(13, 20) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
+3 >Emitted(13, 27) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
 ---
 >>>            var Find;
 1 >^^^^^^^^^^^^
@@ -190,10 +189,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                    		}
   >                    	}
   >                    }
-1 >Emitted(15, 13) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
-2 >Emitted(15, 17) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
-3 >Emitted(15, 21) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
-4 >Emitted(15, 22) Source(42, 2) + SourceIndex(0) name (Sample.Actions.Thing)
+1 >Emitted(14, 13) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
+2 >Emitted(14, 17) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
+3 >Emitted(14, 21) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
+4 >Emitted(14, 22) Source(42, 2) + SourceIndex(0) name (Sample.Actions.Thing)
 ---
 >>>            (function (Find) {
 1->^^^^^^^^^^^^
@@ -207,24 +206,24 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                       Find
 4 >                            
 5 >                             {
-1->Emitted(16, 13) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
-2 >Emitted(16, 24) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
-3 >Emitted(16, 28) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
-4 >Emitted(16, 30) Source(32, 34) + SourceIndex(0) name (Sample.Actions.Thing)
-5 >Emitted(16, 31) Source(32, 35) + SourceIndex(0) name (Sample.Actions.Thing)
+1->Emitted(15, 13) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
+2 >Emitted(15, 24) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
+3 >Emitted(15, 28) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
+4 >Emitted(15, 30) Source(32, 34) + SourceIndex(0) name (Sample.Actions.Thing)
+5 >Emitted(15, 31) Source(32, 35) + SourceIndex(0) name (Sample.Actions.Thing)
 ---
 >>>                var StartFindAction = (function () {
 1->^^^^^^^^^^^^^^^^
 2 >                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1->
   >	
-1->Emitted(17, 17) Source(33, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+1->Emitted(16, 17) Source(33, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find)
 ---
 >>>                    function StartFindAction() {
 1->^^^^^^^^^^^^^^^^^^^^
 2 >                    ^^->
 1->
-1->Emitted(18, 21) Source(33, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+1->Emitted(17, 21) Source(33, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
 ---
 >>>                    }
 1->^^^^^^^^^^^^^^^^^^^^
@@ -240,8 +239,8 @@ sourceFile:recursiveClassReferenceTest.ts
   >		}
   >	
 2 >                    }
-1->Emitted(19, 21) Source(41, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.constructor)
-2 >Emitted(19, 22) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.constructor)
+1->Emitted(18, 21) Source(41, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.constructor)
+2 >Emitted(18, 22) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.constructor)
 ---
 >>>                    StartFindAction.prototype.getId = function () { return "yo"; };
 1->^^^^^^^^^^^^^^^^^^^^
@@ -264,16 +263,16 @@ sourceFile:recursiveClassReferenceTest.ts
 8 >                                                                               ;
 9 >                                                                                 
 10>                                                                                 }
-1->Emitted(20, 21) Source(35, 10) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-2 >Emitted(20, 52) Source(35, 15) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-3 >Emitted(20, 55) Source(35, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-4 >Emitted(20, 69) Source(35, 20) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
-5 >Emitted(20, 75) Source(35, 26) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
-6 >Emitted(20, 76) Source(35, 27) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
-7 >Emitted(20, 80) Source(35, 31) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
-8 >Emitted(20, 81) Source(35, 32) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
-9 >Emitted(20, 82) Source(35, 33) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
-10>Emitted(20, 83) Source(35, 34) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
+1->Emitted(19, 21) Source(35, 10) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+2 >Emitted(19, 52) Source(35, 15) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+3 >Emitted(19, 55) Source(35, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+4 >Emitted(19, 69) Source(35, 20) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
+5 >Emitted(19, 75) Source(35, 26) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
+6 >Emitted(19, 76) Source(35, 27) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
+7 >Emitted(19, 80) Source(35, 31) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
+8 >Emitted(19, 81) Source(35, 32) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
+9 >Emitted(19, 82) Source(35, 33) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
+10>Emitted(19, 83) Source(35, 34) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.getId)
 ---
 >>>                    StartFindAction.prototype.run = function (Thing) {
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -288,11 +287,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                                                 
 4 >                                                    public run(
 5 >                                                              Thing:Sample.Thing.ICodeThing
-1 >Emitted(21, 21) Source(37, 10) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-2 >Emitted(21, 50) Source(37, 13) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-3 >Emitted(21, 53) Source(37, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-4 >Emitted(21, 63) Source(37, 14) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-5 >Emitted(21, 68) Source(37, 43) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+1 >Emitted(20, 21) Source(37, 10) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+2 >Emitted(20, 50) Source(37, 13) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+3 >Emitted(20, 53) Source(37, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+4 >Emitted(20, 63) Source(37, 14) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+5 >Emitted(20, 68) Source(37, 43) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
 ---
 >>>                        return true;
 1 >^^^^^^^^^^^^^^^^^^^^^^^^
@@ -307,11 +306,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                               
 4 >                               true
 5 >                                   ;
-1 >Emitted(22, 25) Source(39, 4) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
-2 >Emitted(22, 31) Source(39, 10) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
-3 >Emitted(22, 32) Source(39, 11) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
-4 >Emitted(22, 36) Source(39, 15) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
-5 >Emitted(22, 37) Source(39, 16) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
+1 >Emitted(21, 25) Source(39, 4) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
+2 >Emitted(21, 31) Source(39, 10) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
+3 >Emitted(21, 32) Source(39, 11) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
+4 >Emitted(21, 36) Source(39, 15) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
+5 >Emitted(21, 37) Source(39, 16) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
 ---
 >>>                    };
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -320,8 +319,8 @@ sourceFile:recursiveClassReferenceTest.ts
 1 >
   >		
 2 >                    }
-1 >Emitted(23, 21) Source(40, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
-2 >Emitted(23, 22) Source(40, 4) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
+1 >Emitted(22, 21) Source(40, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
+2 >Emitted(22, 22) Source(40, 4) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction.run)
 ---
 >>>                    return StartFindAction;
 1->^^^^^^^^^^^^^^^^^^^^
@@ -329,8 +328,8 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
   >	
 2 >                    }
-1->Emitted(24, 21) Source(41, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-2 >Emitted(24, 43) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+1->Emitted(23, 21) Source(41, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+2 >Emitted(23, 43) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
 ---
 >>>                })();
 1 >^^^^^^^^^^^^^^^^
@@ -350,10 +349,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                 			return true;
   >                 		}
   >                 	}
-1 >Emitted(25, 17) Source(41, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-2 >Emitted(25, 18) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
-3 >Emitted(25, 18) Source(33, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find)
-4 >Emitted(25, 22) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+1 >Emitted(24, 17) Source(41, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+2 >Emitted(24, 18) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find.StartFindAction)
+3 >Emitted(24, 18) Source(33, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+4 >Emitted(24, 22) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find)
 ---
 >>>                Find.StartFindAction = StartFindAction;
 1->^^^^^^^^^^^^^^^^
@@ -373,10 +372,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                    		}
   >                                    	}
 4 >                                                      
-1->Emitted(26, 17) Source(33, 15) + SourceIndex(0) name (Sample.Actions.Thing.Find)
-2 >Emitted(26, 37) Source(33, 30) + SourceIndex(0) name (Sample.Actions.Thing.Find)
-3 >Emitted(26, 55) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find)
-4 >Emitted(26, 56) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+1->Emitted(25, 17) Source(33, 15) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+2 >Emitted(25, 37) Source(33, 30) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+3 >Emitted(25, 55) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+4 >Emitted(25, 56) Source(41, 3) + SourceIndex(0) name (Sample.Actions.Thing.Find)
 ---
 >>>            })(Find = Thing_1.Find || (Thing_1.Find = {}));
 1->^^^^^^^^^^^^
@@ -408,15 +407,15 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                                   		}
   >                                                   	}
   >                                                   }
-1->Emitted(27, 13) Source(42, 1) + SourceIndex(0) name (Sample.Actions.Thing.Find)
-2 >Emitted(27, 14) Source(42, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find)
-3 >Emitted(27, 16) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
-4 >Emitted(27, 20) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
-5 >Emitted(27, 23) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
-6 >Emitted(27, 35) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
-7 >Emitted(27, 40) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
-8 >Emitted(27, 52) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
-9 >Emitted(27, 60) Source(42, 2) + SourceIndex(0) name (Sample.Actions.Thing)
+1->Emitted(26, 13) Source(42, 1) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+2 >Emitted(26, 14) Source(42, 2) + SourceIndex(0) name (Sample.Actions.Thing.Find)
+3 >Emitted(26, 16) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
+4 >Emitted(26, 20) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
+5 >Emitted(26, 23) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
+6 >Emitted(26, 35) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
+7 >Emitted(26, 40) Source(32, 29) + SourceIndex(0) name (Sample.Actions.Thing)
+8 >Emitted(26, 52) Source(32, 33) + SourceIndex(0) name (Sample.Actions.Thing)
+9 >Emitted(26, 60) Source(42, 2) + SourceIndex(0) name (Sample.Actions.Thing)
 ---
 >>>        })(Thing = Actions.Thing || (Actions.Thing = {}));
 1 >^^^^^^^^
@@ -448,15 +447,15 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                                  		}
   >                                                  	}
   >                                                  }
-1 >Emitted(28, 9) Source(42, 1) + SourceIndex(0) name (Sample.Actions.Thing)
-2 >Emitted(28, 10) Source(42, 2) + SourceIndex(0) name (Sample.Actions.Thing)
-3 >Emitted(28, 12) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
-4 >Emitted(28, 17) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
-5 >Emitted(28, 20) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
-6 >Emitted(28, 33) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
-7 >Emitted(28, 38) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
-8 >Emitted(28, 51) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
-9 >Emitted(28, 59) Source(42, 2) + SourceIndex(0) name (Sample.Actions)
+1 >Emitted(27, 9) Source(42, 1) + SourceIndex(0) name (Sample.Actions.Thing)
+2 >Emitted(27, 10) Source(42, 2) + SourceIndex(0) name (Sample.Actions.Thing)
+3 >Emitted(27, 12) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
+4 >Emitted(27, 17) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
+5 >Emitted(27, 20) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
+6 >Emitted(27, 33) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
+7 >Emitted(27, 38) Source(32, 23) + SourceIndex(0) name (Sample.Actions)
+8 >Emitted(27, 51) Source(32, 28) + SourceIndex(0) name (Sample.Actions)
+9 >Emitted(27, 59) Source(42, 2) + SourceIndex(0) name (Sample.Actions)
 ---
 >>>    })(Actions = Sample.Actions || (Sample.Actions = {}));
 1->^^^^
@@ -487,15 +486,15 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                                  		}
   >                                                  	}
   >                                                  }
-1->Emitted(29, 5) Source(42, 1) + SourceIndex(0) name (Sample.Actions)
-2 >Emitted(29, 6) Source(42, 2) + SourceIndex(0) name (Sample.Actions)
-3 >Emitted(29, 8) Source(32, 15) + SourceIndex(0) name (Sample)
-4 >Emitted(29, 15) Source(32, 22) + SourceIndex(0) name (Sample)
-5 >Emitted(29, 18) Source(32, 15) + SourceIndex(0) name (Sample)
-6 >Emitted(29, 32) Source(32, 22) + SourceIndex(0) name (Sample)
-7 >Emitted(29, 37) Source(32, 15) + SourceIndex(0) name (Sample)
-8 >Emitted(29, 51) Source(32, 22) + SourceIndex(0) name (Sample)
-9 >Emitted(29, 59) Source(42, 2) + SourceIndex(0) name (Sample)
+1->Emitted(28, 5) Source(42, 1) + SourceIndex(0) name (Sample.Actions)
+2 >Emitted(28, 6) Source(42, 2) + SourceIndex(0) name (Sample.Actions)
+3 >Emitted(28, 8) Source(32, 15) + SourceIndex(0) name (Sample)
+4 >Emitted(28, 15) Source(32, 22) + SourceIndex(0) name (Sample)
+5 >Emitted(28, 18) Source(32, 15) + SourceIndex(0) name (Sample)
+6 >Emitted(28, 32) Source(32, 22) + SourceIndex(0) name (Sample)
+7 >Emitted(28, 37) Source(32, 15) + SourceIndex(0) name (Sample)
+8 >Emitted(28, 51) Source(32, 22) + SourceIndex(0) name (Sample)
+9 >Emitted(28, 59) Source(42, 2) + SourceIndex(0) name (Sample)
 ---
 >>>})(Sample || (Sample = {}));
 1 >
@@ -522,13 +521,13 @@ sourceFile:recursiveClassReferenceTest.ts
   >                    		}
   >                    	}
   >                    }
-1 >Emitted(30, 1) Source(42, 1) + SourceIndex(0) name (Sample)
-2 >Emitted(30, 2) Source(42, 2) + SourceIndex(0) name (Sample)
-3 >Emitted(30, 4) Source(32, 8) + SourceIndex(0)
-4 >Emitted(30, 10) Source(32, 14) + SourceIndex(0)
-5 >Emitted(30, 15) Source(32, 8) + SourceIndex(0)
-6 >Emitted(30, 21) Source(32, 14) + SourceIndex(0)
-7 >Emitted(30, 29) Source(42, 2) + SourceIndex(0)
+1 >Emitted(29, 1) Source(42, 1) + SourceIndex(0) name (Sample)
+2 >Emitted(29, 2) Source(42, 2) + SourceIndex(0) name (Sample)
+3 >Emitted(29, 4) Source(32, 8) + SourceIndex(0)
+4 >Emitted(29, 10) Source(32, 14) + SourceIndex(0)
+5 >Emitted(29, 15) Source(32, 8) + SourceIndex(0)
+6 >Emitted(29, 21) Source(32, 14) + SourceIndex(0)
+7 >Emitted(29, 29) Source(42, 2) + SourceIndex(0)
 ---
 >>>var Sample;
 1 >
@@ -562,10 +561,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >          
   >          	}
   >          }
-1 >Emitted(31, 1) Source(44, 1) + SourceIndex(0)
-2 >Emitted(31, 5) Source(44, 8) + SourceIndex(0)
-3 >Emitted(31, 11) Source(44, 14) + SourceIndex(0)
-4 >Emitted(31, 12) Source(64, 2) + SourceIndex(0)
+1 >Emitted(30, 1) Source(44, 1) + SourceIndex(0)
+2 >Emitted(30, 5) Source(44, 8) + SourceIndex(0)
+3 >Emitted(30, 11) Source(44, 14) + SourceIndex(0)
+4 >Emitted(30, 12) Source(64, 2) + SourceIndex(0)
 ---
 >>>(function (Sample) {
 1->
@@ -574,9 +573,9 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
 2 >module 
 3 >           Sample
-1->Emitted(32, 1) Source(44, 1) + SourceIndex(0)
-2 >Emitted(32, 12) Source(44, 8) + SourceIndex(0)
-3 >Emitted(32, 18) Source(44, 14) + SourceIndex(0)
+1->Emitted(31, 1) Source(44, 1) + SourceIndex(0)
+2 >Emitted(31, 12) Source(44, 8) + SourceIndex(0)
+3 >Emitted(31, 18) Source(44, 14) + SourceIndex(0)
 ---
 >>>    var Thing;
 1 >^^^^
@@ -608,10 +607,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >             
   >             	}
   >             }
-1 >Emitted(33, 5) Source(44, 15) + SourceIndex(0) name (Sample)
-2 >Emitted(33, 9) Source(44, 15) + SourceIndex(0) name (Sample)
-3 >Emitted(33, 14) Source(44, 20) + SourceIndex(0) name (Sample)
-4 >Emitted(33, 15) Source(64, 2) + SourceIndex(0) name (Sample)
+1 >Emitted(32, 5) Source(44, 15) + SourceIndex(0) name (Sample)
+2 >Emitted(32, 9) Source(44, 15) + SourceIndex(0) name (Sample)
+3 >Emitted(32, 14) Source(44, 20) + SourceIndex(0) name (Sample)
+4 >Emitted(32, 15) Source(64, 2) + SourceIndex(0) name (Sample)
 ---
 >>>    (function (Thing) {
 1->^^^^
@@ -621,9 +620,9 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
 2 >    
 3 >               Thing
-1->Emitted(34, 5) Source(44, 15) + SourceIndex(0) name (Sample)
-2 >Emitted(34, 16) Source(44, 15) + SourceIndex(0) name (Sample)
-3 >Emitted(34, 21) Source(44, 20) + SourceIndex(0) name (Sample)
+1->Emitted(33, 5) Source(44, 15) + SourceIndex(0) name (Sample)
+2 >Emitted(33, 16) Source(44, 15) + SourceIndex(0) name (Sample)
+3 >Emitted(33, 21) Source(44, 20) + SourceIndex(0) name (Sample)
 ---
 >>>        var Widgets;
 1->^^^^^^^^
@@ -655,10 +654,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                   
   >                   	}
   >                   }
-1->Emitted(35, 9) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
-2 >Emitted(35, 13) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
-3 >Emitted(35, 20) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
-4 >Emitted(35, 21) Source(64, 2) + SourceIndex(0) name (Sample.Thing)
+1->Emitted(34, 9) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
+2 >Emitted(34, 13) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
+3 >Emitted(34, 20) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
+4 >Emitted(34, 21) Source(64, 2) + SourceIndex(0) name (Sample.Thing)
 ---
 >>>        (function (Widgets) {
 1->^^^^^^^^
@@ -672,18 +671,18 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                   Widgets
 4 >                           
 5 >                            {
-1->Emitted(36, 9) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
-2 >Emitted(36, 20) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
-3 >Emitted(36, 27) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
-4 >Emitted(36, 29) Source(44, 29) + SourceIndex(0) name (Sample.Thing)
-5 >Emitted(36, 30) Source(44, 30) + SourceIndex(0) name (Sample.Thing)
+1->Emitted(35, 9) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
+2 >Emitted(35, 20) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
+3 >Emitted(35, 27) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
+4 >Emitted(35, 29) Source(44, 29) + SourceIndex(0) name (Sample.Thing)
+5 >Emitted(35, 30) Source(44, 30) + SourceIndex(0) name (Sample.Thing)
 ---
 >>>            var FindWidget = (function () {
 1->^^^^^^^^^^^^
 2 >            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1->
   >	
-1->Emitted(37, 13) Source(45, 2) + SourceIndex(0) name (Sample.Thing.Widgets)
+1->Emitted(36, 13) Source(45, 2) + SourceIndex(0) name (Sample.Thing.Widgets)
 ---
 >>>                function FindWidget(codeThing) {
 1->^^^^^^^^^^^^^^^^
@@ -698,9 +697,9 @@ sourceFile:recursiveClassReferenceTest.ts
   >		
 2 >                constructor(private 
 3 >                                    codeThing: Sample.Thing.ICodeThing
-1->Emitted(38, 17) Source(50, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-2 >Emitted(38, 37) Source(50, 23) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-3 >Emitted(38, 46) Source(50, 57) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+1->Emitted(37, 17) Source(50, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+2 >Emitted(37, 37) Source(50, 23) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+3 >Emitted(37, 46) Source(50, 57) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
 ---
 >>>                    this.codeThing = codeThing;
 1->^^^^^^^^^^^^^^^^^^^^
@@ -713,11 +712,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                                  
 4 >                                     codeThing
 5 >                                              : Sample.Thing.ICodeThing
-1->Emitted(39, 21) Source(50, 23) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-2 >Emitted(39, 35) Source(50, 32) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-3 >Emitted(39, 38) Source(50, 23) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-4 >Emitted(39, 47) Source(50, 32) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-5 >Emitted(39, 48) Source(50, 57) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+1->Emitted(38, 21) Source(50, 23) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+2 >Emitted(38, 35) Source(50, 32) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+3 >Emitted(38, 38) Source(50, 23) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+4 >Emitted(38, 47) Source(50, 32) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+5 >Emitted(38, 48) Source(50, 57) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
 ---
 >>>                    this.domNode = null;
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -730,11 +729,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                                :any = 
 4 >                                   null
 5 >                                       ;
-1 >Emitted(40, 21) Source(49, 11) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-2 >Emitted(40, 33) Source(49, 18) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-3 >Emitted(40, 36) Source(49, 25) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-4 >Emitted(40, 40) Source(49, 29) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-5 >Emitted(40, 41) Source(49, 30) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+1 >Emitted(39, 21) Source(49, 11) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+2 >Emitted(39, 33) Source(49, 18) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+3 >Emitted(39, 36) Source(49, 25) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+4 >Emitted(39, 40) Source(49, 29) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+5 >Emitted(39, 41) Source(49, 30) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
 ---
 >>>                    // scenario 1
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -747,9 +746,9 @@ sourceFile:recursiveClassReferenceTest.ts
   >		    
 2 >                    
 3 >                    // scenario 1
-1 >Emitted(41, 21) Source(52, 7) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-2 >Emitted(41, 21) Source(51, 7) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-3 >Emitted(41, 34) Source(51, 20) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+1 >Emitted(40, 21) Source(52, 7) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+2 >Emitted(40, 21) Source(51, 7) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+3 >Emitted(40, 34) Source(51, 20) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
 ---
 >>>                    codeThing.addWidget("addWidget", this);
 1->^^^^^^^^^^^^^^^^^^^^
@@ -773,16 +772,16 @@ sourceFile:recursiveClassReferenceTest.ts
 8 >                                                     this
 9 >                                                         )
 10>                                                          ;
-1->Emitted(42, 21) Source(52, 7) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-2 >Emitted(42, 30) Source(52, 16) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-3 >Emitted(42, 31) Source(52, 17) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-4 >Emitted(42, 40) Source(52, 26) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-5 >Emitted(42, 41) Source(52, 27) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-6 >Emitted(42, 52) Source(52, 38) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-7 >Emitted(42, 54) Source(52, 40) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-8 >Emitted(42, 58) Source(52, 44) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-9 >Emitted(42, 59) Source(52, 45) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-10>Emitted(42, 60) Source(52, 46) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+1->Emitted(41, 21) Source(52, 7) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+2 >Emitted(41, 30) Source(52, 16) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+3 >Emitted(41, 31) Source(52, 17) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+4 >Emitted(41, 40) Source(52, 26) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+5 >Emitted(41, 41) Source(52, 27) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+6 >Emitted(41, 52) Source(52, 38) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+7 >Emitted(41, 54) Source(52, 40) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+8 >Emitted(41, 58) Source(52, 44) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+9 >Emitted(41, 59) Source(52, 45) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+10>Emitted(41, 60) Source(52, 46) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
 ---
 >>>                }
 1 >^^^^^^^^^^^^^^^^
@@ -791,8 +790,8 @@ sourceFile:recursiveClassReferenceTest.ts
 1 >
   >		
 2 >                }
-1 >Emitted(43, 17) Source(53, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
-2 >Emitted(43, 18) Source(53, 4) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+1 >Emitted(42, 17) Source(53, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
+2 >Emitted(42, 18) Source(53, 4) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.constructor)
 ---
 >>>                FindWidget.prototype.gar = function (runner) { if (true) {
 1->^^^^^^^^^^^^^^^^
@@ -821,19 +820,19 @@ sourceFile:recursiveClassReferenceTest.ts
 11>                                                                       )
 12>                                                                         
 13>                                                                         {
-1->Emitted(44, 17) Source(47, 10) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-2 >Emitted(44, 41) Source(47, 13) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-3 >Emitted(44, 44) Source(47, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-4 >Emitted(44, 54) Source(47, 14) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-5 >Emitted(44, 60) Source(47, 55) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-6 >Emitted(44, 64) Source(47, 59) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-7 >Emitted(44, 66) Source(47, 61) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-8 >Emitted(44, 67) Source(47, 62) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-9 >Emitted(44, 68) Source(47, 63) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-10>Emitted(44, 72) Source(47, 67) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-11>Emitted(44, 73) Source(47, 68) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-12>Emitted(44, 74) Source(47, 69) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-13>Emitted(44, 75) Source(47, 70) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+1->Emitted(43, 17) Source(47, 10) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+2 >Emitted(43, 41) Source(47, 13) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+3 >Emitted(43, 44) Source(47, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+4 >Emitted(43, 54) Source(47, 14) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+5 >Emitted(43, 60) Source(47, 55) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+6 >Emitted(43, 64) Source(47, 59) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+7 >Emitted(43, 66) Source(47, 61) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+8 >Emitted(43, 67) Source(47, 62) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+9 >Emitted(43, 68) Source(47, 63) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+10>Emitted(43, 72) Source(47, 67) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+11>Emitted(43, 73) Source(47, 68) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+12>Emitted(43, 74) Source(47, 69) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+13>Emitted(43, 75) Source(47, 70) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
 ---
 >>>                    return runner(this);
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -852,14 +851,14 @@ sourceFile:recursiveClassReferenceTest.ts
 6 >                                  this
 7 >                                      )
 8 >                                       ;
-1 >Emitted(45, 21) Source(47, 70) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-2 >Emitted(45, 27) Source(47, 76) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-3 >Emitted(45, 28) Source(47, 77) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-4 >Emitted(45, 34) Source(47, 83) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-5 >Emitted(45, 35) Source(47, 84) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-6 >Emitted(45, 39) Source(47, 88) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-7 >Emitted(45, 40) Source(47, 89) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-8 >Emitted(45, 41) Source(47, 90) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+1 >Emitted(44, 21) Source(47, 70) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+2 >Emitted(44, 27) Source(47, 76) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+3 >Emitted(44, 28) Source(47, 77) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+4 >Emitted(44, 34) Source(47, 83) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+5 >Emitted(44, 35) Source(47, 84) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+6 >Emitted(44, 39) Source(47, 88) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+7 >Emitted(44, 40) Source(47, 89) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+8 >Emitted(44, 41) Source(47, 90) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
 ---
 >>>                } };
 1 >^^^^^^^^^^^^^^^^
@@ -871,10 +870,10 @@ sourceFile:recursiveClassReferenceTest.ts
 2 >                }
 3 >                 
 4 >                  }
-1 >Emitted(46, 17) Source(47, 90) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-2 >Emitted(46, 18) Source(47, 91) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-3 >Emitted(46, 19) Source(47, 91) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
-4 >Emitted(46, 20) Source(47, 92) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+1 >Emitted(45, 17) Source(47, 90) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+2 >Emitted(45, 18) Source(47, 91) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+3 >Emitted(45, 19) Source(47, 91) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
+4 >Emitted(45, 20) Source(47, 92) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.gar)
 ---
 >>>                FindWidget.prototype.getDomNode = function () {
 1->^^^^^^^^^^^^^^^^
@@ -891,9 +890,9 @@ sourceFile:recursiveClassReferenceTest.ts
   >		public 
 2 >                getDomNode
 3 >                                               
-1->Emitted(47, 17) Source(55, 10) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-2 >Emitted(47, 48) Source(55, 20) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-3 >Emitted(47, 51) Source(55, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+1->Emitted(46, 17) Source(55, 10) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+2 >Emitted(46, 48) Source(55, 20) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+3 >Emitted(46, 51) Source(55, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
 ---
 >>>                    return domNode;
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -907,11 +906,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                           
 4 >                           domNode
 5 >                                  ;
-1 >Emitted(48, 21) Source(56, 4) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
-2 >Emitted(48, 27) Source(56, 10) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
-3 >Emitted(48, 28) Source(56, 11) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
-4 >Emitted(48, 35) Source(56, 18) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
-5 >Emitted(48, 36) Source(56, 19) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
+1 >Emitted(47, 21) Source(56, 4) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
+2 >Emitted(47, 27) Source(56, 10) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
+3 >Emitted(47, 28) Source(56, 11) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
+4 >Emitted(47, 35) Source(56, 18) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
+5 >Emitted(47, 36) Source(56, 19) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
 ---
 >>>                };
 1 >^^^^^^^^^^^^^^^^
@@ -920,8 +919,8 @@ sourceFile:recursiveClassReferenceTest.ts
 1 >
   >		
 2 >                }
-1 >Emitted(49, 17) Source(57, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
-2 >Emitted(49, 18) Source(57, 4) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
+1 >Emitted(48, 17) Source(57, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
+2 >Emitted(48, 18) Source(57, 4) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.getDomNode)
 ---
 >>>                FindWidget.prototype.destroy = function () {
 1->^^^^^^^^^^^^^^^^
@@ -932,9 +931,9 @@ sourceFile:recursiveClassReferenceTest.ts
   >		public 
 2 >                destroy
 3 >                                            
-1->Emitted(50, 17) Source(59, 10) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-2 >Emitted(50, 45) Source(59, 17) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-3 >Emitted(50, 48) Source(59, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+1->Emitted(49, 17) Source(59, 10) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+2 >Emitted(49, 45) Source(59, 17) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+3 >Emitted(49, 48) Source(59, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
 ---
 >>>                };
 1 >^^^^^^^^^^^^^^^^
@@ -944,8 +943,8 @@ sourceFile:recursiveClassReferenceTest.ts
   >
   >		
 2 >                }
-1 >Emitted(51, 17) Source(61, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.destroy)
-2 >Emitted(51, 18) Source(61, 4) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.destroy)
+1 >Emitted(50, 17) Source(61, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.destroy)
+2 >Emitted(50, 18) Source(61, 4) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget.destroy)
 ---
 >>>                return FindWidget;
 1->^^^^^^^^^^^^^^^^
@@ -954,8 +953,8 @@ sourceFile:recursiveClassReferenceTest.ts
   >
   >	
 2 >                }
-1->Emitted(52, 17) Source(63, 2) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-2 >Emitted(52, 34) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+1->Emitted(51, 17) Source(63, 2) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+2 >Emitted(51, 34) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
 ---
 >>>            })();
 1 >^^^^^^^^^^^^
@@ -985,10 +984,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >             		}
   >             
   >             	}
-1 >Emitted(53, 13) Source(63, 2) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-2 >Emitted(53, 14) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
-3 >Emitted(53, 14) Source(45, 2) + SourceIndex(0) name (Sample.Thing.Widgets)
-4 >Emitted(53, 18) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets)
+1 >Emitted(52, 13) Source(63, 2) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+2 >Emitted(52, 14) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets.FindWidget)
+3 >Emitted(52, 14) Source(45, 2) + SourceIndex(0) name (Sample.Thing.Widgets)
+4 >Emitted(52, 18) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets)
 ---
 >>>            Widgets.FindWidget = FindWidget;
 1->^^^^^^^^^^^^
@@ -1018,10 +1017,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                              
   >                              	}
 4 >                                           
-1->Emitted(54, 13) Source(45, 15) + SourceIndex(0) name (Sample.Thing.Widgets)
-2 >Emitted(54, 31) Source(45, 25) + SourceIndex(0) name (Sample.Thing.Widgets)
-3 >Emitted(54, 44) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets)
-4 >Emitted(54, 45) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets)
+1->Emitted(53, 13) Source(45, 15) + SourceIndex(0) name (Sample.Thing.Widgets)
+2 >Emitted(53, 31) Source(45, 25) + SourceIndex(0) name (Sample.Thing.Widgets)
+3 >Emitted(53, 44) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets)
+4 >Emitted(53, 45) Source(63, 3) + SourceIndex(0) name (Sample.Thing.Widgets)
 ---
 >>>        })(Widgets = Thing.Widgets || (Thing.Widgets = {}));
 1->^^^^^^^^
@@ -1063,15 +1062,15 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                                    
   >                                                    	}
   >                                                    }
-1->Emitted(55, 9) Source(64, 1) + SourceIndex(0) name (Sample.Thing.Widgets)
-2 >Emitted(55, 10) Source(64, 2) + SourceIndex(0) name (Sample.Thing.Widgets)
-3 >Emitted(55, 12) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
-4 >Emitted(55, 19) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
-5 >Emitted(55, 22) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
-6 >Emitted(55, 35) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
-7 >Emitted(55, 40) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
-8 >Emitted(55, 53) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
-9 >Emitted(55, 61) Source(64, 2) + SourceIndex(0) name (Sample.Thing)
+1->Emitted(54, 9) Source(64, 1) + SourceIndex(0) name (Sample.Thing.Widgets)
+2 >Emitted(54, 10) Source(64, 2) + SourceIndex(0) name (Sample.Thing.Widgets)
+3 >Emitted(54, 12) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
+4 >Emitted(54, 19) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
+5 >Emitted(54, 22) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
+6 >Emitted(54, 35) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
+7 >Emitted(54, 40) Source(44, 21) + SourceIndex(0) name (Sample.Thing)
+8 >Emitted(54, 53) Source(44, 28) + SourceIndex(0) name (Sample.Thing)
+9 >Emitted(54, 61) Source(64, 2) + SourceIndex(0) name (Sample.Thing)
 ---
 >>>    })(Thing = Sample.Thing || (Sample.Thing = {}));
 1 >^^^^
@@ -1112,15 +1111,15 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                            
   >                                            	}
   >                                            }
-1 >Emitted(56, 5) Source(64, 1) + SourceIndex(0) name (Sample.Thing)
-2 >Emitted(56, 6) Source(64, 2) + SourceIndex(0) name (Sample.Thing)
-3 >Emitted(56, 8) Source(44, 15) + SourceIndex(0) name (Sample)
-4 >Emitted(56, 13) Source(44, 20) + SourceIndex(0) name (Sample)
-5 >Emitted(56, 16) Source(44, 15) + SourceIndex(0) name (Sample)
-6 >Emitted(56, 28) Source(44, 20) + SourceIndex(0) name (Sample)
-7 >Emitted(56, 33) Source(44, 15) + SourceIndex(0) name (Sample)
-8 >Emitted(56, 45) Source(44, 20) + SourceIndex(0) name (Sample)
-9 >Emitted(56, 53) Source(64, 2) + SourceIndex(0) name (Sample)
+1 >Emitted(55, 5) Source(64, 1) + SourceIndex(0) name (Sample.Thing)
+2 >Emitted(55, 6) Source(64, 2) + SourceIndex(0) name (Sample.Thing)
+3 >Emitted(55, 8) Source(44, 15) + SourceIndex(0) name (Sample)
+4 >Emitted(55, 13) Source(44, 20) + SourceIndex(0) name (Sample)
+5 >Emitted(55, 16) Source(44, 15) + SourceIndex(0) name (Sample)
+6 >Emitted(55, 28) Source(44, 20) + SourceIndex(0) name (Sample)
+7 >Emitted(55, 33) Source(44, 15) + SourceIndex(0) name (Sample)
+8 >Emitted(55, 45) Source(44, 20) + SourceIndex(0) name (Sample)
+9 >Emitted(55, 53) Source(64, 2) + SourceIndex(0) name (Sample)
 ---
 >>>})(Sample || (Sample = {}));
 1 >
@@ -1158,13 +1157,13 @@ sourceFile:recursiveClassReferenceTest.ts
   >                    
   >                    	}
   >                    }
-1 >Emitted(57, 1) Source(64, 1) + SourceIndex(0) name (Sample)
-2 >Emitted(57, 2) Source(64, 2) + SourceIndex(0) name (Sample)
-3 >Emitted(57, 4) Source(44, 8) + SourceIndex(0)
-4 >Emitted(57, 10) Source(44, 14) + SourceIndex(0)
-5 >Emitted(57, 15) Source(44, 8) + SourceIndex(0)
-6 >Emitted(57, 21) Source(44, 14) + SourceIndex(0)
-7 >Emitted(57, 29) Source(64, 2) + SourceIndex(0)
+1 >Emitted(56, 1) Source(64, 1) + SourceIndex(0) name (Sample)
+2 >Emitted(56, 2) Source(64, 2) + SourceIndex(0) name (Sample)
+3 >Emitted(56, 4) Source(44, 8) + SourceIndex(0)
+4 >Emitted(56, 10) Source(44, 14) + SourceIndex(0)
+5 >Emitted(56, 15) Source(44, 8) + SourceIndex(0)
+6 >Emitted(56, 21) Source(44, 14) + SourceIndex(0)
+7 >Emitted(56, 29) Source(64, 2) + SourceIndex(0)
 ---
 >>>var AbstractMode = (function () {
 1->
@@ -1173,13 +1172,13 @@ sourceFile:recursiveClassReferenceTest.ts
   >
   >interface IMode { getInitialState(): IState;} 
   >
-1->Emitted(58, 1) Source(67, 1) + SourceIndex(0)
+1->Emitted(57, 1) Source(67, 1) + SourceIndex(0)
 ---
 >>>    function AbstractMode() {
 1->^^^^
 2 >    ^^->
 1->
-1->Emitted(59, 5) Source(67, 1) + SourceIndex(0) name (AbstractMode)
+1->Emitted(58, 5) Source(67, 1) + SourceIndex(0) name (AbstractMode)
 ---
 >>>    }
 1->^^^^
@@ -1187,8 +1186,8 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1->class AbstractMode implements IMode { public getInitialState(): IState { return null;} 
 2 >    }
-1->Emitted(60, 5) Source(67, 88) + SourceIndex(0) name (AbstractMode.constructor)
-2 >Emitted(60, 6) Source(67, 89) + SourceIndex(0) name (AbstractMode.constructor)
+1->Emitted(59, 5) Source(67, 88) + SourceIndex(0) name (AbstractMode.constructor)
+2 >Emitted(59, 6) Source(67, 89) + SourceIndex(0) name (AbstractMode.constructor)
 ---
 >>>    AbstractMode.prototype.getInitialState = function () { return null; };
 1->^^^^
@@ -1211,24 +1210,24 @@ sourceFile:recursiveClassReferenceTest.ts
 8 >                                                                      ;
 9 >                                                                       
 10>                                                                        }
-1->Emitted(61, 5) Source(67, 46) + SourceIndex(0) name (AbstractMode)
-2 >Emitted(61, 43) Source(67, 61) + SourceIndex(0) name (AbstractMode)
-3 >Emitted(61, 46) Source(67, 39) + SourceIndex(0) name (AbstractMode)
-4 >Emitted(61, 60) Source(67, 74) + SourceIndex(0) name (AbstractMode.getInitialState)
-5 >Emitted(61, 66) Source(67, 80) + SourceIndex(0) name (AbstractMode.getInitialState)
-6 >Emitted(61, 67) Source(67, 81) + SourceIndex(0) name (AbstractMode.getInitialState)
-7 >Emitted(61, 71) Source(67, 85) + SourceIndex(0) name (AbstractMode.getInitialState)
-8 >Emitted(61, 72) Source(67, 86) + SourceIndex(0) name (AbstractMode.getInitialState)
-9 >Emitted(61, 73) Source(67, 86) + SourceIndex(0) name (AbstractMode.getInitialState)
-10>Emitted(61, 74) Source(67, 87) + SourceIndex(0) name (AbstractMode.getInitialState)
+1->Emitted(60, 5) Source(67, 46) + SourceIndex(0) name (AbstractMode)
+2 >Emitted(60, 43) Source(67, 61) + SourceIndex(0) name (AbstractMode)
+3 >Emitted(60, 46) Source(67, 39) + SourceIndex(0) name (AbstractMode)
+4 >Emitted(60, 60) Source(67, 74) + SourceIndex(0) name (AbstractMode.getInitialState)
+5 >Emitted(60, 66) Source(67, 80) + SourceIndex(0) name (AbstractMode.getInitialState)
+6 >Emitted(60, 67) Source(67, 81) + SourceIndex(0) name (AbstractMode.getInitialState)
+7 >Emitted(60, 71) Source(67, 85) + SourceIndex(0) name (AbstractMode.getInitialState)
+8 >Emitted(60, 72) Source(67, 86) + SourceIndex(0) name (AbstractMode.getInitialState)
+9 >Emitted(60, 73) Source(67, 86) + SourceIndex(0) name (AbstractMode.getInitialState)
+10>Emitted(60, 74) Source(67, 87) + SourceIndex(0) name (AbstractMode.getInitialState)
 ---
 >>>    return AbstractMode;
 1 >^^^^
 2 >    ^^^^^^^^^^^^^^^^^^^
 1 > 
 2 >    }
-1 >Emitted(62, 5) Source(67, 88) + SourceIndex(0) name (AbstractMode)
-2 >Emitted(62, 24) Source(67, 89) + SourceIndex(0) name (AbstractMode)
+1 >Emitted(61, 5) Source(67, 88) + SourceIndex(0) name (AbstractMode)
+2 >Emitted(61, 24) Source(67, 89) + SourceIndex(0) name (AbstractMode)
 ---
 >>>})();
 1 >
@@ -1240,10 +1239,10 @@ sourceFile:recursiveClassReferenceTest.ts
 2 >}
 3 > 
 4 > class AbstractMode implements IMode { public getInitialState(): IState { return null;} }
-1 >Emitted(63, 1) Source(67, 88) + SourceIndex(0) name (AbstractMode)
-2 >Emitted(63, 2) Source(67, 89) + SourceIndex(0) name (AbstractMode)
-3 >Emitted(63, 2) Source(67, 1) + SourceIndex(0)
-4 >Emitted(63, 6) Source(67, 89) + SourceIndex(0)
+1 >Emitted(62, 1) Source(67, 88) + SourceIndex(0) name (AbstractMode)
+2 >Emitted(62, 2) Source(67, 89) + SourceIndex(0) name (AbstractMode)
+3 >Emitted(62, 2) Source(67, 1) + SourceIndex(0)
+4 >Emitted(62, 6) Source(67, 89) + SourceIndex(0)
 ---
 >>>var Sample;
 1->
@@ -1288,10 +1287,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >          
   >          	}
   >          }
-1->Emitted(64, 1) Source(76, 1) + SourceIndex(0)
-2 >Emitted(64, 5) Source(76, 8) + SourceIndex(0)
-3 >Emitted(64, 11) Source(76, 14) + SourceIndex(0)
-4 >Emitted(64, 12) Source(100, 2) + SourceIndex(0)
+1->Emitted(63, 1) Source(76, 1) + SourceIndex(0)
+2 >Emitted(63, 5) Source(76, 8) + SourceIndex(0)
+3 >Emitted(63, 11) Source(76, 14) + SourceIndex(0)
+4 >Emitted(63, 12) Source(100, 2) + SourceIndex(0)
 ---
 >>>(function (Sample) {
 1->
@@ -1300,9 +1299,9 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
 2 >module 
 3 >           Sample
-1->Emitted(65, 1) Source(76, 1) + SourceIndex(0)
-2 >Emitted(65, 12) Source(76, 8) + SourceIndex(0)
-3 >Emitted(65, 18) Source(76, 14) + SourceIndex(0)
+1->Emitted(64, 1) Source(76, 1) + SourceIndex(0)
+2 >Emitted(64, 12) Source(76, 8) + SourceIndex(0)
+3 >Emitted(64, 18) Source(76, 14) + SourceIndex(0)
 ---
 >>>    var Thing;
 1 >^^^^
@@ -1338,10 +1337,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >             
   >             	}
   >             }
-1 >Emitted(66, 5) Source(76, 15) + SourceIndex(0) name (Sample)
-2 >Emitted(66, 9) Source(76, 15) + SourceIndex(0) name (Sample)
-3 >Emitted(66, 14) Source(76, 20) + SourceIndex(0) name (Sample)
-4 >Emitted(66, 15) Source(100, 2) + SourceIndex(0) name (Sample)
+1 >Emitted(65, 5) Source(76, 15) + SourceIndex(0) name (Sample)
+2 >Emitted(65, 9) Source(76, 15) + SourceIndex(0) name (Sample)
+3 >Emitted(65, 14) Source(76, 20) + SourceIndex(0) name (Sample)
+4 >Emitted(65, 15) Source(100, 2) + SourceIndex(0) name (Sample)
 ---
 >>>    (function (Thing) {
 1->^^^^
@@ -1351,9 +1350,9 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
 2 >    
 3 >               Thing
-1->Emitted(67, 5) Source(76, 15) + SourceIndex(0) name (Sample)
-2 >Emitted(67, 16) Source(76, 15) + SourceIndex(0) name (Sample)
-3 >Emitted(67, 21) Source(76, 20) + SourceIndex(0) name (Sample)
+1->Emitted(66, 5) Source(76, 15) + SourceIndex(0) name (Sample)
+2 >Emitted(66, 16) Source(76, 15) + SourceIndex(0) name (Sample)
+3 >Emitted(66, 21) Source(76, 20) + SourceIndex(0) name (Sample)
 ---
 >>>        var Languages;
 1->^^^^^^^^
@@ -1389,10 +1388,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                     
   >                     	}
   >                     }
-1->Emitted(68, 9) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
-2 >Emitted(68, 13) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
-3 >Emitted(68, 22) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
-4 >Emitted(68, 23) Source(100, 2) + SourceIndex(0) name (Sample.Thing)
+1->Emitted(67, 9) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
+2 >Emitted(67, 13) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
+3 >Emitted(67, 22) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
+4 >Emitted(67, 23) Source(100, 2) + SourceIndex(0) name (Sample.Thing)
 ---
 >>>        (function (Languages) {
 1->^^^^^^^^
@@ -1401,9 +1400,9 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
 2 >        
 3 >                   Languages
-1->Emitted(69, 9) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
-2 >Emitted(69, 20) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
-3 >Emitted(69, 29) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
+1->Emitted(68, 9) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
+2 >Emitted(68, 20) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
+3 >Emitted(68, 29) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
 ---
 >>>            var PlainText;
 1 >^^^^^^^^^^^^
@@ -1439,10 +1438,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                         
   >                         	}
   >                         }
-1 >Emitted(70, 13) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
-2 >Emitted(70, 17) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
-3 >Emitted(70, 26) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
-4 >Emitted(70, 27) Source(100, 2) + SourceIndex(0) name (Sample.Thing.Languages)
+1 >Emitted(69, 13) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
+2 >Emitted(69, 17) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
+3 >Emitted(69, 26) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
+4 >Emitted(69, 27) Source(100, 2) + SourceIndex(0) name (Sample.Thing.Languages)
 ---
 >>>            (function (PlainText) {
 1->^^^^^^^^^^^^
@@ -1456,11 +1455,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                       PlainText
 4 >                                 
 5 >                                  {
-1->Emitted(71, 13) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
-2 >Emitted(71, 24) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
-3 >Emitted(71, 33) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
-4 >Emitted(71, 35) Source(76, 41) + SourceIndex(0) name (Sample.Thing.Languages)
-5 >Emitted(71, 36) Source(76, 42) + SourceIndex(0) name (Sample.Thing.Languages)
+1->Emitted(70, 13) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
+2 >Emitted(70, 24) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
+3 >Emitted(70, 33) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
+4 >Emitted(70, 35) Source(76, 41) + SourceIndex(0) name (Sample.Thing.Languages)
+5 >Emitted(70, 36) Source(76, 42) + SourceIndex(0) name (Sample.Thing.Languages)
 ---
 >>>                var State = (function () {
 1->^^^^^^^^^^^^^^^^
@@ -1468,7 +1467,7 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
   >	
   >	
-1->Emitted(72, 17) Source(78, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+1->Emitted(71, 17) Source(78, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
 ---
 >>>                    function State(mode) {
 1->^^^^^^^^^^^^^^^^^^^^
@@ -1479,9 +1478,9 @@ sourceFile:recursiveClassReferenceTest.ts
   >        
 2 >                    constructor(private 
 3 >                                   mode: IMode
-1->Emitted(73, 21) Source(79, 9) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-2 >Emitted(73, 36) Source(79, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-3 >Emitted(73, 40) Source(79, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+1->Emitted(72, 21) Source(79, 9) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+2 >Emitted(72, 36) Source(79, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+3 >Emitted(72, 40) Source(79, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
 ---
 >>>                        this.mode = mode;
 1->^^^^^^^^^^^^^^^^^^^^^^^^
@@ -1494,11 +1493,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                                 
 4 >                                    mode
 5 >                                        : IMode
-1->Emitted(74, 25) Source(79, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
-2 >Emitted(74, 34) Source(79, 33) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
-3 >Emitted(74, 37) Source(79, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
-4 >Emitted(74, 41) Source(79, 33) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
-5 >Emitted(74, 42) Source(79, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
+1->Emitted(73, 25) Source(79, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
+2 >Emitted(73, 34) Source(79, 33) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
+3 >Emitted(73, 37) Source(79, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
+4 >Emitted(73, 41) Source(79, 33) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
+5 >Emitted(73, 42) Source(79, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
 ---
 >>>                    }
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -1506,8 +1505,8 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >) { 
 2 >                    }
-1 >Emitted(75, 21) Source(79, 44) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
-2 >Emitted(75, 22) Source(79, 45) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
+1 >Emitted(74, 21) Source(79, 44) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
+2 >Emitted(74, 22) Source(79, 45) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.constructor)
 ---
 >>>                    State.prototype.clone = function () {
 1->^^^^^^^^^^^^^^^^^^^^
@@ -1517,9 +1516,9 @@ sourceFile:recursiveClassReferenceTest.ts
   >		public 
 2 >                    clone
 3 >                                         
-1->Emitted(76, 21) Source(80, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-2 >Emitted(76, 42) Source(80, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-3 >Emitted(76, 45) Source(80, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+1->Emitted(75, 21) Source(80, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+2 >Emitted(75, 42) Source(80, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+3 >Emitted(75, 45) Source(80, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
 ---
 >>>                        return this;
 1 >^^^^^^^^^^^^^^^^^^^^^^^^
@@ -1533,11 +1532,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                               
 4 >                               this
 5 >                                   ;
-1 >Emitted(77, 25) Source(81, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
-2 >Emitted(77, 31) Source(81, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
-3 >Emitted(77, 32) Source(81, 11) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
-4 >Emitted(77, 36) Source(81, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
-5 >Emitted(77, 37) Source(81, 16) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
+1 >Emitted(76, 25) Source(81, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
+2 >Emitted(76, 31) Source(81, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
+3 >Emitted(76, 32) Source(81, 11) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
+4 >Emitted(76, 36) Source(81, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
+5 >Emitted(76, 37) Source(81, 16) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
 ---
 >>>                    };
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -1546,8 +1545,8 @@ sourceFile:recursiveClassReferenceTest.ts
 1 >
   >		
 2 >                    }
-1 >Emitted(78, 21) Source(82, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
-2 >Emitted(78, 22) Source(82, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
+1 >Emitted(77, 21) Source(82, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
+2 >Emitted(77, 22) Source(82, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.clone)
 ---
 >>>                    State.prototype.equals = function (other) {
 1->^^^^^^^^^^^^^^^^^^^^
@@ -1562,11 +1561,11 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                                          
 4 >                                             public equals(
 5 >                                                       other:IState
-1->Emitted(79, 21) Source(84, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-2 >Emitted(79, 43) Source(84, 16) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-3 >Emitted(79, 46) Source(84, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-4 >Emitted(79, 56) Source(84, 17) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-5 >Emitted(79, 61) Source(84, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+1->Emitted(78, 21) Source(84, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+2 >Emitted(78, 43) Source(84, 16) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+3 >Emitted(78, 46) Source(84, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+4 >Emitted(78, 56) Source(84, 17) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+5 >Emitted(78, 61) Source(84, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
 ---
 >>>                        return this === other;
 1 >^^^^^^^^^^^^^^^^^^^^^^^^
@@ -1584,13 +1583,13 @@ sourceFile:recursiveClassReferenceTest.ts
 5 >                                    === 
 6 >                                        other
 7 >                                             ;
-1 >Emitted(80, 25) Source(85, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
-2 >Emitted(80, 31) Source(85, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
-3 >Emitted(80, 32) Source(85, 11) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
-4 >Emitted(80, 36) Source(85, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
-5 >Emitted(80, 41) Source(85, 20) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
-6 >Emitted(80, 46) Source(85, 25) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
-7 >Emitted(80, 47) Source(85, 26) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+1 >Emitted(79, 25) Source(85, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+2 >Emitted(79, 31) Source(85, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+3 >Emitted(79, 32) Source(85, 11) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+4 >Emitted(79, 36) Source(85, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+5 >Emitted(79, 41) Source(85, 20) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+6 >Emitted(79, 46) Source(85, 25) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+7 >Emitted(79, 47) Source(85, 26) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
 ---
 >>>                    };
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -1599,8 +1598,8 @@ sourceFile:recursiveClassReferenceTest.ts
 1 >
   >		
 2 >                    }
-1 >Emitted(81, 21) Source(86, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
-2 >Emitted(81, 22) Source(86, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+1 >Emitted(80, 21) Source(86, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
+2 >Emitted(80, 22) Source(86, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.equals)
 ---
 >>>                    State.prototype.getMode = function () { return mode; };
 1->^^^^^^^^^^^^^^^^^^^^
@@ -1625,16 +1624,16 @@ sourceFile:recursiveClassReferenceTest.ts
 8 >                                                                       ;
 9 >                                                                         
 10>                                                                         }
-1->Emitted(82, 21) Source(88, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-2 >Emitted(82, 44) Source(88, 17) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-3 >Emitted(82, 47) Source(88, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-4 >Emitted(82, 61) Source(88, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
-5 >Emitted(82, 67) Source(88, 35) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
-6 >Emitted(82, 68) Source(88, 36) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
-7 >Emitted(82, 72) Source(88, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
-8 >Emitted(82, 73) Source(88, 41) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
-9 >Emitted(82, 74) Source(88, 42) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
-10>Emitted(82, 75) Source(88, 43) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
+1->Emitted(81, 21) Source(88, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+2 >Emitted(81, 44) Source(88, 17) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+3 >Emitted(81, 47) Source(88, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+4 >Emitted(81, 61) Source(88, 29) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
+5 >Emitted(81, 67) Source(88, 35) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
+6 >Emitted(81, 68) Source(88, 36) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
+7 >Emitted(81, 72) Source(88, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
+8 >Emitted(81, 73) Source(88, 41) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
+9 >Emitted(81, 74) Source(88, 42) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
+10>Emitted(81, 75) Source(88, 43) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State.getMode)
 ---
 >>>                    return State;
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -1642,8 +1641,8 @@ sourceFile:recursiveClassReferenceTest.ts
 1 >
   >	
 2 >                    }
-1 >Emitted(83, 21) Source(89, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-2 >Emitted(83, 33) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+1 >Emitted(82, 21) Source(89, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+2 >Emitted(82, 33) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
 ---
 >>>                })();
 1 >^^^^^^^^^^^^^^^^
@@ -1666,10 +1665,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                 		
   >                 		public getMode(): IMode { return mode; }
   >                 	}
-1 >Emitted(84, 17) Source(89, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-2 >Emitted(84, 18) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
-3 >Emitted(84, 18) Source(78, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-4 >Emitted(84, 22) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+1 >Emitted(83, 17) Source(89, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+2 >Emitted(83, 18) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.State)
+3 >Emitted(83, 18) Source(78, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+4 >Emitted(83, 22) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
 ---
 >>>                PlainText.State = State;
 1->^^^^^^^^^^^^^^^^
@@ -1692,10 +1691,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                               		public getMode(): IMode { return mode; }
   >                               	}
 4 >                                       
-1->Emitted(85, 17) Source(78, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-2 >Emitted(85, 32) Source(78, 20) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-3 >Emitted(85, 40) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-4 >Emitted(85, 41) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+1->Emitted(84, 17) Source(78, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+2 >Emitted(84, 32) Source(78, 20) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+3 >Emitted(84, 40) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+4 >Emitted(84, 41) Source(89, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
 ---
 >>>                var Mode = (function (_super) {
 1->^^^^^^^^^^^^^^^^
@@ -1703,29 +1702,29 @@ sourceFile:recursiveClassReferenceTest.ts
 1->
   >	
   >	
-1->Emitted(86, 17) Source(91, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+1->Emitted(85, 17) Source(91, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
 ---
 >>>                    __extends(Mode, _super);
 1->^^^^^^^^^^^^^^^^^^^^
 2 >                    ^^^^^^^^^^^^^^^^^^^^^^^^
 1->export class Mode extends 
 2 >                    AbstractMode
-1->Emitted(87, 21) Source(91, 28) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
-2 >Emitted(87, 45) Source(91, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+1->Emitted(86, 21) Source(91, 28) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+2 >Emitted(86, 45) Source(91, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
 ---
 >>>                    function Mode() {
 1 >^^^^^^^^^^^^^^^^^^^^
 2 >                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
-1 >Emitted(88, 21) Source(91, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+1 >Emitted(87, 21) Source(91, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
 ---
 >>>                        _super.apply(this, arguments);
 1->^^^^^^^^^^^^^^^^^^^^^^^^
 2 >                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1->export class Mode extends 
 2 >                        AbstractMode
-1->Emitted(89, 25) Source(91, 28) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.constructor)
-2 >Emitted(89, 55) Source(91, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.constructor)
+1->Emitted(88, 25) Source(91, 28) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.constructor)
+2 >Emitted(88, 55) Source(91, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.constructor)
 ---
 >>>                    }
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -1741,8 +1740,8 @@ sourceFile:recursiveClassReferenceTest.ts
   >
   >	
 2 >                    }
-1 >Emitted(90, 21) Source(99, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.constructor)
-2 >Emitted(90, 22) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.constructor)
+1 >Emitted(89, 21) Source(99, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.constructor)
+2 >Emitted(89, 22) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.constructor)
 ---
 >>>                    // scenario 2
 1->^^^^^^^^^^^^^^^^^^^^
@@ -1750,8 +1749,8 @@ sourceFile:recursiveClassReferenceTest.ts
 3 >                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1->
 2 >                    // scenario 2
-1->Emitted(91, 21) Source(93, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
-2 >Emitted(91, 34) Source(93, 16) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+1->Emitted(90, 21) Source(93, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+2 >Emitted(90, 34) Source(93, 16) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
 ---
 >>>                    Mode.prototype.getInitialState = function () {
 1->^^^^^^^^^^^^^^^^^^^^
@@ -1761,9 +1760,9 @@ sourceFile:recursiveClassReferenceTest.ts
   >		public 
 2 >                    getInitialState
 3 >                                                  
-1->Emitted(92, 21) Source(94, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
-2 >Emitted(92, 51) Source(94, 25) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
-3 >Emitted(92, 54) Source(94, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+1->Emitted(91, 21) Source(94, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+2 >Emitted(91, 51) Source(94, 25) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+3 >Emitted(91, 54) Source(94, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
 ---
 >>>                        return new State(self);
 1 >^^^^^^^^^^^^^^^^^^^^^^^^
@@ -1785,15 +1784,15 @@ sourceFile:recursiveClassReferenceTest.ts
 7 >                                         self
 8 >                                             )
 9 >                                              ;
-1 >Emitted(93, 25) Source(95, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-2 >Emitted(93, 31) Source(95, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-3 >Emitted(93, 32) Source(95, 11) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-4 >Emitted(93, 36) Source(95, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-5 >Emitted(93, 41) Source(95, 20) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-6 >Emitted(93, 42) Source(95, 21) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-7 >Emitted(93, 46) Source(95, 25) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-8 >Emitted(93, 47) Source(95, 26) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-9 >Emitted(93, 48) Source(95, 27) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+1 >Emitted(92, 25) Source(95, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+2 >Emitted(92, 31) Source(95, 10) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+3 >Emitted(92, 32) Source(95, 11) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+4 >Emitted(92, 36) Source(95, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+5 >Emitted(92, 41) Source(95, 20) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+6 >Emitted(92, 42) Source(95, 21) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+7 >Emitted(92, 46) Source(95, 25) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+8 >Emitted(92, 47) Source(95, 26) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+9 >Emitted(92, 48) Source(95, 27) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
 ---
 >>>                    };
 1 >^^^^^^^^^^^^^^^^^^^^
@@ -1802,8 +1801,8 @@ sourceFile:recursiveClassReferenceTest.ts
 1 >
   >		
 2 >                    }
-1 >Emitted(94, 21) Source(96, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
-2 >Emitted(94, 22) Source(96, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+1 >Emitted(93, 21) Source(96, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
+2 >Emitted(93, 22) Source(96, 4) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode.getInitialState)
 ---
 >>>                    return Mode;
 1->^^^^^^^^^^^^^^^^^^^^
@@ -1814,8 +1813,8 @@ sourceFile:recursiveClassReferenceTest.ts
   >
   >	
 2 >                    }
-1->Emitted(95, 21) Source(99, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
-2 >Emitted(95, 32) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+1->Emitted(94, 21) Source(99, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+2 >Emitted(94, 32) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
 ---
 >>>                })(AbstractMode);
 1->^^^^^^^^^^^^^^^^
@@ -1839,12 +1838,12 @@ sourceFile:recursiveClassReferenceTest.ts
   >                               
   >                               
   >                               	}
-1->Emitted(96, 17) Source(99, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
-2 >Emitted(96, 18) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
-3 >Emitted(96, 18) Source(91, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-4 >Emitted(96, 20) Source(91, 28) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-5 >Emitted(96, 32) Source(91, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-6 >Emitted(96, 34) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+1->Emitted(95, 17) Source(99, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+2 >Emitted(95, 18) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText.Mode)
+3 >Emitted(95, 18) Source(91, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+4 >Emitted(95, 20) Source(91, 28) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+5 >Emitted(95, 32) Source(91, 40) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+6 >Emitted(95, 34) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
 ---
 >>>                PlainText.Mode = Mode;
 1->^^^^^^^^^^^^^^^^
@@ -1864,10 +1863,10 @@ sourceFile:recursiveClassReferenceTest.ts
   >                              
   >                              	}
 4 >                                     
-1->Emitted(97, 17) Source(91, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-2 >Emitted(97, 31) Source(91, 19) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-3 >Emitted(97, 38) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-4 >Emitted(97, 39) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+1->Emitted(96, 17) Source(91, 15) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+2 >Emitted(96, 31) Source(91, 19) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+3 >Emitted(96, 38) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+4 >Emitted(96, 39) Source(99, 3) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
 ---
 >>>            })(PlainText = Languages.PlainText || (Languages.PlainText = {}));
 1->^^^^^^^^^^^^
@@ -1913,15 +1912,15 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                                                      
   >                                                                      	}
   >                                                                      }
-1->Emitted(98, 13) Source(100, 1) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-2 >Emitted(98, 14) Source(100, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
-3 >Emitted(98, 16) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
-4 >Emitted(98, 25) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
-5 >Emitted(98, 28) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
-6 >Emitted(98, 47) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
-7 >Emitted(98, 52) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
-8 >Emitted(98, 71) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
-9 >Emitted(98, 79) Source(100, 2) + SourceIndex(0) name (Sample.Thing.Languages)
+1->Emitted(97, 13) Source(100, 1) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+2 >Emitted(97, 14) Source(100, 2) + SourceIndex(0) name (Sample.Thing.Languages.PlainText)
+3 >Emitted(97, 16) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
+4 >Emitted(97, 25) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
+5 >Emitted(97, 28) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
+6 >Emitted(97, 47) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
+7 >Emitted(97, 52) Source(76, 31) + SourceIndex(0) name (Sample.Thing.Languages)
+8 >Emitted(97, 71) Source(76, 40) + SourceIndex(0) name (Sample.Thing.Languages)
+9 >Emitted(97, 79) Source(100, 2) + SourceIndex(0) name (Sample.Thing.Languages)
 ---
 >>>        })(Languages = Thing.Languages || (Thing.Languages = {}));
 1 >^^^^^^^^
@@ -1966,15 +1965,15 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                                          
   >                                                          	}
   >                                                          }
-1 >Emitted(99, 9) Source(100, 1) + SourceIndex(0) name (Sample.Thing.Languages)
-2 >Emitted(99, 10) Source(100, 2) + SourceIndex(0) name (Sample.Thing.Languages)
-3 >Emitted(99, 12) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
-4 >Emitted(99, 21) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
-5 >Emitted(99, 24) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
-6 >Emitted(99, 39) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
-7 >Emitted(99, 44) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
-8 >Emitted(99, 59) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
-9 >Emitted(99, 67) Source(100, 2) + SourceIndex(0) name (Sample.Thing)
+1 >Emitted(98, 9) Source(100, 1) + SourceIndex(0) name (Sample.Thing.Languages)
+2 >Emitted(98, 10) Source(100, 2) + SourceIndex(0) name (Sample.Thing.Languages)
+3 >Emitted(98, 12) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
+4 >Emitted(98, 21) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
+5 >Emitted(98, 24) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
+6 >Emitted(98, 39) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
+7 >Emitted(98, 44) Source(76, 21) + SourceIndex(0) name (Sample.Thing)
+8 >Emitted(98, 59) Source(76, 30) + SourceIndex(0) name (Sample.Thing)
+9 >Emitted(98, 67) Source(100, 2) + SourceIndex(0) name (Sample.Thing)
 ---
 >>>    })(Thing = Sample.Thing || (Sample.Thing = {}));
 1 >^^^^
@@ -2019,15 +2018,15 @@ sourceFile:recursiveClassReferenceTest.ts
   >                                            
   >                                            	}
   >                                            }
-1 >Emitted(100, 5) Source(100, 1) + SourceIndex(0) name (Sample.Thing)
-2 >Emitted(100, 6) Source(100, 2) + SourceIndex(0) name (Sample.Thing)
-3 >Emitted(100, 8) Source(76, 15) + SourceIndex(0) name (Sample)
-4 >Emitted(100, 13) Source(76, 20) + SourceIndex(0) name (Sample)
-5 >Emitted(100, 16) Source(76, 15) + SourceIndex(0) name (Sample)
-6 >Emitted(100, 28) Source(76, 20) + SourceIndex(0) name (Sample)
-7 >Emitted(100, 33) Source(76, 15) + SourceIndex(0) name (Sample)
-8 >Emitted(100, 45) Source(76, 20) + SourceIndex(0) name (Sample)
-9 >Emitted(100, 53) Source(100, 2) + SourceIndex(0) name (Sample)
+1 >Emitted(99, 5) Source(100, 1) + SourceIndex(0) name (Sample.Thing)
+2 >Emitted(99, 6) Source(100, 2) + SourceIndex(0) name (Sample.Thing)
+3 >Emitted(99, 8) Source(76, 15) + SourceIndex(0) name (Sample)
+4 >Emitted(99, 13) Source(76, 20) + SourceIndex(0) name (Sample)
+5 >Emitted(99, 16) Source(76, 15) + SourceIndex(0) name (Sample)
+6 >Emitted(99, 28) Source(76, 20) + SourceIndex(0) name (Sample)
+7 >Emitted(99, 33) Source(76, 15) + SourceIndex(0) name (Sample)
+8 >Emitted(99, 45) Source(76, 20) + SourceIndex(0) name (Sample)
+9 >Emitted(99, 53) Source(100, 2) + SourceIndex(0) name (Sample)
 ---
 >>>})(Sample || (Sample = {}));
 1 >
@@ -2069,12 +2068,12 @@ sourceFile:recursiveClassReferenceTest.ts
   >                    
   >                    	}
   >                    }
-1 >Emitted(101, 1) Source(100, 1) + SourceIndex(0) name (Sample)
-2 >Emitted(101, 2) Source(100, 2) + SourceIndex(0) name (Sample)
-3 >Emitted(101, 4) Source(76, 8) + SourceIndex(0)
-4 >Emitted(101, 10) Source(76, 14) + SourceIndex(0)
-5 >Emitted(101, 15) Source(76, 8) + SourceIndex(0)
-6 >Emitted(101, 21) Source(76, 14) + SourceIndex(0)
-7 >Emitted(101, 29) Source(100, 2) + SourceIndex(0)
+1 >Emitted(100, 1) Source(100, 1) + SourceIndex(0) name (Sample)
+2 >Emitted(100, 2) Source(100, 2) + SourceIndex(0) name (Sample)
+3 >Emitted(100, 4) Source(76, 8) + SourceIndex(0)
+4 >Emitted(100, 10) Source(76, 14) + SourceIndex(0)
+5 >Emitted(100, 15) Source(76, 8) + SourceIndex(0)
+6 >Emitted(100, 21) Source(76, 14) + SourceIndex(0)
+7 >Emitted(100, 29) Source(100, 2) + SourceIndex(0)
 ---
 >>>//# sourceMappingURL=recursiveClassReferenceTest.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/recursiveComplicatedClasses.js b/tests/baselines/reference/recursiveComplicatedClasses.js
index 6e88dd8dc2..e35931008b 100644
--- a/tests/baselines/reference/recursiveComplicatedClasses.js
+++ b/tests/baselines/reference/recursiveComplicatedClasses.js
@@ -28,8 +28,7 @@ class TypeSymbol extends InferenceSymbol {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Signature = (function () {
     function Signature() {
diff --git a/tests/baselines/reference/recursivelySpecializedConstructorDeclaration.js b/tests/baselines/reference/recursivelySpecializedConstructorDeclaration.js
index 60022dc245..48e8b1c4eb 100644
--- a/tests/baselines/reference/recursivelySpecializedConstructorDeclaration.js
+++ b/tests/baselines/reference/recursivelySpecializedConstructorDeclaration.js
@@ -33,8 +33,7 @@ declare module MsPortal.Controls.Base.ItemList {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var MsPortal;
 (function (MsPortal) {
diff --git a/tests/baselines/reference/resolvingClassDeclarationWhenInBaseTypeResolution.js b/tests/baselines/reference/resolvingClassDeclarationWhenInBaseTypeResolution.js
index 72cc702309..3ba03a1e03 100644
--- a/tests/baselines/reference/resolvingClassDeclarationWhenInBaseTypeResolution.js
+++ b/tests/baselines/reference/resolvingClassDeclarationWhenInBaseTypeResolution.js
@@ -1023,8 +1023,7 @@ module caurinus {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var rionegrensis;
 (function (rionegrensis) {
diff --git a/tests/baselines/reference/returnInConstructor1.js b/tests/baselines/reference/returnInConstructor1.js
index 87b1b6d672..e8781f06d2 100644
--- a/tests/baselines/reference/returnInConstructor1.js
+++ b/tests/baselines/reference/returnInConstructor1.js
@@ -70,8 +70,7 @@ class I extends G {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/returnStatements.js b/tests/baselines/reference/returnStatements.js
index 35c208b19e..956efc5f07 100644
--- a/tests/baselines/reference/returnStatements.js
+++ b/tests/baselines/reference/returnStatements.js
@@ -28,8 +28,7 @@ function fn13(): C { return null; }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // all the following should be valid
 function fn1() { return 1; }
diff --git a/tests/baselines/reference/scopeCheckExtendedClassInsidePublicMethod2.js b/tests/baselines/reference/scopeCheckExtendedClassInsidePublicMethod2.js
index f971f08974..1a5fc7d9b3 100644
--- a/tests/baselines/reference/scopeCheckExtendedClassInsidePublicMethod2.js
+++ b/tests/baselines/reference/scopeCheckExtendedClassInsidePublicMethod2.js
@@ -12,8 +12,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/scopeCheckExtendedClassInsideStaticMethod1.js b/tests/baselines/reference/scopeCheckExtendedClassInsideStaticMethod1.js
index a7f7f4fde9..2844897bdd 100644
--- a/tests/baselines/reference/scopeCheckExtendedClassInsideStaticMethod1.js
+++ b/tests/baselines/reference/scopeCheckExtendedClassInsideStaticMethod1.js
@@ -12,8 +12,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/scopeTests.js b/tests/baselines/reference/scopeTests.js
index 99a933cf15..b104f63f74 100644
--- a/tests/baselines/reference/scopeTests.js
+++ b/tests/baselines/reference/scopeTests.js
@@ -15,8 +15,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/shadowPrivateMembers.js b/tests/baselines/reference/shadowPrivateMembers.js
index 4100dba13e..e2ac679e7e 100644
--- a/tests/baselines/reference/shadowPrivateMembers.js
+++ b/tests/baselines/reference/shadowPrivateMembers.js
@@ -7,8 +7,7 @@ class derived extends base { private n() {} }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var base = (function () {
     function base() {
diff --git a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js
index cae6e991e2..f210e65d4d 100644
--- a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js
+++ b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js
@@ -11,8 +11,7 @@ class Greeter extends AbstractGreeter {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var AbstractGreeter = (function () {
     function AbstractGreeter() {
diff --git a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map
index 60a2684504..fad366e8eb 100644
--- a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map
+++ b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map
@@ -1,2 +1,2 @@
 //// [sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map]
-{"version":3,"file":"sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js","sourceRoot":"","sources":["sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts"],"names":["AbstractGreeter","AbstractGreeter.constructor","Greeter","Greeter.constructor"],"mappings":";;;;;;AAAA;IAAAA;IACAC,CAACA;IAADD,sBAACA;AAADA,CAACA,AADD,IACC;AAED;IAAsBE,2BAAeA;IAArCA;QAAsBC,8BAAeA;QAC1BA,MAACA,GAAGA,EAAEA,CAACA;QACPA,UAAKA,GAAGA,KAAKA,CAACA;IACzBA,CAACA;IAADD,cAACA;AAADA,CAACA,AAHD,EAAsB,eAAe,EAGpC"}
\ No newline at end of file
+{"version":3,"file":"sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js","sourceRoot":"","sources":["sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts"],"names":["AbstractGreeter","AbstractGreeter.constructor","Greeter","Greeter.constructor"],"mappings":";;;;;AAAA;IAAAA;IACAC,CAACA;IAADD,sBAACA;AAADA,CAACA,AADD,IACC;AAED;IAAsBE,2BAAeA;IAArCA;QAAsBC,8BAAeA;QAC1BA,MAACA,GAAGA,EAAEA,CAACA;QACPA,UAAKA,GAAGA,KAAKA,CAACA;IACzBA,CAACA;IAADD,cAACA;AAADA,CAACA,AAHD,EAAsB,eAAe,EAGpC"}
\ No newline at end of file
diff --git a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.sourcemap.txt b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.sourcemap.txt
index d0934f3c9e..aba9861a23 100644
--- a/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.sourcemap.txt
+++ b/tests/baselines/reference/sourceMapValidationClassWithDefaultConstructorAndExtendsClause.sourcemap.txt
@@ -11,20 +11,19 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 >>>var __extends = (this && this.__extends) || function (d, b) {
 >>>    for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
 >>>    function __() { this.constructor = d; }
->>>    __.prototype = b.prototype;
->>>    d.prototype = new __();
+>>>    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 >>>};
 >>>var AbstractGreeter = (function () {
 1 >
 2 >^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
-1 >Emitted(7, 1) Source(1, 1) + SourceIndex(0)
+1 >Emitted(6, 1) Source(1, 1) + SourceIndex(0)
 ---
 >>>    function AbstractGreeter() {
 1->^^^^
 2 >    ^^->
 1->
-1->Emitted(8, 5) Source(1, 1) + SourceIndex(0) name (AbstractGreeter)
+1->Emitted(7, 5) Source(1, 1) + SourceIndex(0) name (AbstractGreeter)
 ---
 >>>    }
 1->^^^^
@@ -33,16 +32,16 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 1->class AbstractGreeter {
   >
 2 >    }
-1->Emitted(9, 5) Source(2, 1) + SourceIndex(0) name (AbstractGreeter.constructor)
-2 >Emitted(9, 6) Source(2, 2) + SourceIndex(0) name (AbstractGreeter.constructor)
+1->Emitted(8, 5) Source(2, 1) + SourceIndex(0) name (AbstractGreeter.constructor)
+2 >Emitted(8, 6) Source(2, 2) + SourceIndex(0) name (AbstractGreeter.constructor)
 ---
 >>>    return AbstractGreeter;
 1->^^^^
 2 >    ^^^^^^^^^^^^^^^^^^^^^^
 1->
 2 >    }
-1->Emitted(10, 5) Source(2, 1) + SourceIndex(0) name (AbstractGreeter)
-2 >Emitted(10, 27) Source(2, 2) + SourceIndex(0) name (AbstractGreeter)
+1->Emitted(9, 5) Source(2, 1) + SourceIndex(0) name (AbstractGreeter)
+2 >Emitted(9, 27) Source(2, 2) + SourceIndex(0) name (AbstractGreeter)
 ---
 >>>})();
 1 >
@@ -55,10 +54,10 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 3 > 
 4 > class AbstractGreeter {
   > }
-1 >Emitted(11, 1) Source(2, 1) + SourceIndex(0) name (AbstractGreeter)
-2 >Emitted(11, 2) Source(2, 2) + SourceIndex(0) name (AbstractGreeter)
-3 >Emitted(11, 2) Source(1, 1) + SourceIndex(0)
-4 >Emitted(11, 6) Source(2, 2) + SourceIndex(0)
+1 >Emitted(10, 1) Source(2, 1) + SourceIndex(0) name (AbstractGreeter)
+2 >Emitted(10, 2) Source(2, 2) + SourceIndex(0) name (AbstractGreeter)
+3 >Emitted(10, 2) Source(1, 1) + SourceIndex(0)
+4 >Emitted(10, 6) Source(2, 2) + SourceIndex(0)
 ---
 >>>var Greeter = (function (_super) {
 1->
@@ -66,29 +65,29 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 1->
   >
   >
-1->Emitted(12, 1) Source(4, 1) + SourceIndex(0)
+1->Emitted(11, 1) Source(4, 1) + SourceIndex(0)
 ---
 >>>    __extends(Greeter, _super);
 1->^^^^
 2 >    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1->class Greeter extends 
 2 >    AbstractGreeter
-1->Emitted(13, 5) Source(4, 23) + SourceIndex(0) name (Greeter)
-2 >Emitted(13, 32) Source(4, 38) + SourceIndex(0) name (Greeter)
+1->Emitted(12, 5) Source(4, 23) + SourceIndex(0) name (Greeter)
+2 >Emitted(12, 32) Source(4, 38) + SourceIndex(0) name (Greeter)
 ---
 >>>    function Greeter() {
 1 >^^^^
 2 >    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^->
 1 >
-1 >Emitted(14, 5) Source(4, 1) + SourceIndex(0) name (Greeter)
+1 >Emitted(13, 5) Source(4, 1) + SourceIndex(0) name (Greeter)
 ---
 >>>        _super.apply(this, arguments);
 1->^^^^^^^^
 2 >        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 1->class Greeter extends 
 2 >        AbstractGreeter
-1->Emitted(15, 9) Source(4, 23) + SourceIndex(0) name (Greeter.constructor)
-2 >Emitted(15, 39) Source(4, 38) + SourceIndex(0) name (Greeter.constructor)
+1->Emitted(14, 9) Source(4, 23) + SourceIndex(0) name (Greeter.constructor)
+2 >Emitted(14, 39) Source(4, 38) + SourceIndex(0) name (Greeter.constructor)
 ---
 >>>        this.a = 10;
 1 >^^^^^^^^
@@ -103,11 +102,11 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 3 >               = 
 4 >                 10
 5 >                   ;
-1 >Emitted(16, 9) Source(5, 12) + SourceIndex(0) name (Greeter.constructor)
-2 >Emitted(16, 15) Source(5, 13) + SourceIndex(0) name (Greeter.constructor)
-3 >Emitted(16, 18) Source(5, 16) + SourceIndex(0) name (Greeter.constructor)
-4 >Emitted(16, 20) Source(5, 18) + SourceIndex(0) name (Greeter.constructor)
-5 >Emitted(16, 21) Source(5, 19) + SourceIndex(0) name (Greeter.constructor)
+1 >Emitted(15, 9) Source(5, 12) + SourceIndex(0) name (Greeter.constructor)
+2 >Emitted(15, 15) Source(5, 13) + SourceIndex(0) name (Greeter.constructor)
+3 >Emitted(15, 18) Source(5, 16) + SourceIndex(0) name (Greeter.constructor)
+4 >Emitted(15, 20) Source(5, 18) + SourceIndex(0) name (Greeter.constructor)
+5 >Emitted(15, 21) Source(5, 19) + SourceIndex(0) name (Greeter.constructor)
 ---
 >>>        this.nameA = "Ten";
 1->^^^^^^^^
@@ -121,11 +120,11 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 3 >                   = 
 4 >                     "Ten"
 5 >                          ;
-1->Emitted(17, 9) Source(6, 12) + SourceIndex(0) name (Greeter.constructor)
-2 >Emitted(17, 19) Source(6, 17) + SourceIndex(0) name (Greeter.constructor)
-3 >Emitted(17, 22) Source(6, 20) + SourceIndex(0) name (Greeter.constructor)
-4 >Emitted(17, 27) Source(6, 25) + SourceIndex(0) name (Greeter.constructor)
-5 >Emitted(17, 28) Source(6, 26) + SourceIndex(0) name (Greeter.constructor)
+1->Emitted(16, 9) Source(6, 12) + SourceIndex(0) name (Greeter.constructor)
+2 >Emitted(16, 19) Source(6, 17) + SourceIndex(0) name (Greeter.constructor)
+3 >Emitted(16, 22) Source(6, 20) + SourceIndex(0) name (Greeter.constructor)
+4 >Emitted(16, 27) Source(6, 25) + SourceIndex(0) name (Greeter.constructor)
+5 >Emitted(16, 28) Source(6, 26) + SourceIndex(0) name (Greeter.constructor)
 ---
 >>>    }
 1 >^^^^
@@ -134,8 +133,8 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 1 >
   >
 2 >    }
-1 >Emitted(18, 5) Source(7, 1) + SourceIndex(0) name (Greeter.constructor)
-2 >Emitted(18, 6) Source(7, 2) + SourceIndex(0) name (Greeter.constructor)
+1 >Emitted(17, 5) Source(7, 1) + SourceIndex(0) name (Greeter.constructor)
+2 >Emitted(17, 6) Source(7, 2) + SourceIndex(0) name (Greeter.constructor)
 ---
 >>>    return Greeter;
 1->^^^^
@@ -143,8 +142,8 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
 3 >                  ^^^->
 1->
 2 >    }
-1->Emitted(19, 5) Source(7, 1) + SourceIndex(0) name (Greeter)
-2 >Emitted(19, 19) Source(7, 2) + SourceIndex(0) name (Greeter)
+1->Emitted(18, 5) Source(7, 1) + SourceIndex(0) name (Greeter)
+2 >Emitted(18, 19) Source(7, 2) + SourceIndex(0) name (Greeter)
 ---
 >>>})(AbstractGreeter);
 1->
@@ -163,11 +162,11 @@ sourceFile:sourceMapValidationClassWithDefaultConstructorAndExtendsClause.ts
   >                      public a = 10;
   >                      public nameA = "Ten";
   >                  }
-1->Emitted(20, 1) Source(7, 1) + SourceIndex(0) name (Greeter)
-2 >Emitted(20, 2) Source(7, 2) + SourceIndex(0) name (Greeter)
-3 >Emitted(20, 2) Source(4, 1) + SourceIndex(0)
-4 >Emitted(20, 4) Source(4, 23) + SourceIndex(0)
-5 >Emitted(20, 19) Source(4, 38) + SourceIndex(0)
-6 >Emitted(20, 21) Source(7, 2) + SourceIndex(0)
+1->Emitted(19, 1) Source(7, 1) + SourceIndex(0) name (Greeter)
+2 >Emitted(19, 2) Source(7, 2) + SourceIndex(0) name (Greeter)
+3 >Emitted(19, 2) Source(4, 1) + SourceIndex(0)
+4 >Emitted(19, 4) Source(4, 23) + SourceIndex(0)
+5 >Emitted(19, 19) Source(4, 38) + SourceIndex(0)
+6 >Emitted(19, 21) Source(7, 2) + SourceIndex(0)
 ---
 >>>//# sourceMappingURL=sourceMapValidationClassWithDefaultConstructorAndExtendsClause.js.map
\ No newline at end of file
diff --git a/tests/baselines/reference/specializedInheritedConstructors1.js b/tests/baselines/reference/specializedInheritedConstructors1.js
index ec467ad987..20ef13c3f0 100644
--- a/tests/baselines/reference/specializedInheritedConstructors1.js
+++ b/tests/baselines/reference/specializedInheritedConstructors1.js
@@ -21,8 +21,7 @@ var myView = new MyView(m); // was error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var View = (function () {
     function View(options) {
diff --git a/tests/baselines/reference/specializedOverloadWithRestParameters.js b/tests/baselines/reference/specializedOverloadWithRestParameters.js
index 2a022cdf7d..31cb4a6959 100644
--- a/tests/baselines/reference/specializedOverloadWithRestParameters.js
+++ b/tests/baselines/reference/specializedOverloadWithRestParameters.js
@@ -16,8 +16,7 @@ function g(tagName: any): Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/staticFactory1.js b/tests/baselines/reference/staticFactory1.js
index 96303af586..03092a16de 100644
--- a/tests/baselines/reference/staticFactory1.js
+++ b/tests/baselines/reference/staticFactory1.js
@@ -17,8 +17,7 @@ d.foo();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/staticInheritance.js b/tests/baselines/reference/staticInheritance.js
index 0aba29b356..d3e14d482c 100644
--- a/tests/baselines/reference/staticInheritance.js
+++ b/tests/baselines/reference/staticInheritance.js
@@ -15,8 +15,7 @@ doThing(B); //OK
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function doThing(x) { }
 var A = (function () {
diff --git a/tests/baselines/reference/staticMemberAccessOffDerivedType1.js b/tests/baselines/reference/staticMemberAccessOffDerivedType1.js
index ab3c010d57..8f9849af05 100644
--- a/tests/baselines/reference/staticMemberAccessOffDerivedType1.js
+++ b/tests/baselines/reference/staticMemberAccessOffDerivedType1.js
@@ -13,8 +13,7 @@ class P extends SomeBase {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var SomeBase = (function () {
     function SomeBase() {
diff --git a/tests/baselines/reference/staticPropSuper.js b/tests/baselines/reference/staticPropSuper.js
index f0d50b3ecb..3f75dc8e26 100644
--- a/tests/baselines/reference/staticPropSuper.js
+++ b/tests/baselines/reference/staticPropSuper.js
@@ -39,8 +39,7 @@ class E extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/strictModeInConstructor.js b/tests/baselines/reference/strictModeInConstructor.js
index fef1ef46b1..7fd74aa108 100644
--- a/tests/baselines/reference/strictModeInConstructor.js
+++ b/tests/baselines/reference/strictModeInConstructor.js
@@ -64,8 +64,7 @@ class Ds extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/strictModeReservedWordInClassDeclaration.js b/tests/baselines/reference/strictModeReservedWordInClassDeclaration.js
index 9ee817182c..e4bef79137 100644
--- a/tests/baselines/reference/strictModeReservedWordInClassDeclaration.js
+++ b/tests/baselines/reference/strictModeReservedWordInClassDeclaration.js
@@ -32,8 +32,7 @@ class H extends package.A { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo(private, public, static) {
diff --git a/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.js b/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.js
index b6bd2dbd43..97e3e9b0f5 100644
--- a/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.js
+++ b/tests/baselines/reference/stringIndexerConstrainsPropertyDeclarations2.js
@@ -44,8 +44,7 @@ var b: { [x: string]: A } = {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/subtypesOfTypeParameter.js b/tests/baselines/reference/subtypesOfTypeParameter.js
index 5abdd63342..c7b14a4129 100644
--- a/tests/baselines/reference/subtypesOfTypeParameter.js
+++ b/tests/baselines/reference/subtypesOfTypeParameter.js
@@ -110,8 +110,7 @@ function f2<T, U>(x: T, y: U) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C3 = (function () {
     function C3() {
diff --git a/tests/baselines/reference/subtypesOfTypeParameterWithConstraints.js b/tests/baselines/reference/subtypesOfTypeParameterWithConstraints.js
index afe9b998bd..194c183514 100644
--- a/tests/baselines/reference/subtypesOfTypeParameterWithConstraints.js
+++ b/tests/baselines/reference/subtypesOfTypeParameterWithConstraints.js
@@ -172,8 +172,7 @@ class D29<T extends U, U extends V, V extends Date> extends C3<V> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C3 = (function () {
     function C3() {
diff --git a/tests/baselines/reference/subtypesOfTypeParameterWithConstraints4.js b/tests/baselines/reference/subtypesOfTypeParameterWithConstraints4.js
index 6f1756912a..370bbf2b8f 100644
--- a/tests/baselines/reference/subtypesOfTypeParameterWithConstraints4.js
+++ b/tests/baselines/reference/subtypesOfTypeParameterWithConstraints4.js
@@ -83,8 +83,7 @@ class D9<T extends Foo, U extends Foo, V> extends B1<U> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/subtypesOfTypeParameterWithRecursiveConstraints.js b/tests/baselines/reference/subtypesOfTypeParameterWithRecursiveConstraints.js
index 3d2b637230..c5d4e68b51 100644
--- a/tests/baselines/reference/subtypesOfTypeParameterWithRecursiveConstraints.js
+++ b/tests/baselines/reference/subtypesOfTypeParameterWithRecursiveConstraints.js
@@ -162,8 +162,7 @@ module M2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Foo = (function () {
     function Foo() {
diff --git a/tests/baselines/reference/subtypingTransitivity.js b/tests/baselines/reference/subtypingTransitivity.js
index 9dcb4095aa..9bc5cd9320 100644
--- a/tests/baselines/reference/subtypingTransitivity.js
+++ b/tests/baselines/reference/subtypingTransitivity.js
@@ -23,8 +23,7 @@ b.x = 1; // assigned number to string
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B = (function () {
     function B() {
diff --git a/tests/baselines/reference/subtypingWithCallSignatures2.js b/tests/baselines/reference/subtypingWithCallSignatures2.js
index db6f1d8595..f11b83c4da 100644
--- a/tests/baselines/reference/subtypingWithCallSignatures2.js
+++ b/tests/baselines/reference/subtypingWithCallSignatures2.js
@@ -177,8 +177,7 @@ var r18 = foo18(r18arg1);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithCallSignatures3.js b/tests/baselines/reference/subtypingWithCallSignatures3.js
index d7ff8a79b6..2b45b75b95 100644
--- a/tests/baselines/reference/subtypingWithCallSignatures3.js
+++ b/tests/baselines/reference/subtypingWithCallSignatures3.js
@@ -124,8 +124,7 @@ module WithGenericSignaturesInBaseType {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Errors;
 (function (Errors) {
diff --git a/tests/baselines/reference/subtypingWithCallSignatures4.js b/tests/baselines/reference/subtypingWithCallSignatures4.js
index 739e3cacd8..d1d30437cd 100644
--- a/tests/baselines/reference/subtypingWithCallSignatures4.js
+++ b/tests/baselines/reference/subtypingWithCallSignatures4.js
@@ -116,8 +116,7 @@ var r18 = foo18(r18arg);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures2.js b/tests/baselines/reference/subtypingWithConstructSignatures2.js
index 4e93ddbbe5..df050ffd6e 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures2.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures2.js
@@ -177,8 +177,7 @@ var r18 = foo18(r18arg1);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures3.js b/tests/baselines/reference/subtypingWithConstructSignatures3.js
index 7022b4b395..ccc6fb872c 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures3.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures3.js
@@ -126,8 +126,7 @@ module WithGenericSignaturesInBaseType {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Errors;
 (function (Errors) {
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures4.js b/tests/baselines/reference/subtypingWithConstructSignatures4.js
index a16ea8e239..67b83aa94c 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures4.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures4.js
@@ -116,8 +116,7 @@ var r18 = foo18(r18arg);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures5.js b/tests/baselines/reference/subtypingWithConstructSignatures5.js
index fe3b86d177..ec3bad2c1f 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures5.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures5.js
@@ -54,8 +54,7 @@ interface I extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithConstructSignatures6.js b/tests/baselines/reference/subtypingWithConstructSignatures6.js
index 990b654bf4..1c7a2d883c 100644
--- a/tests/baselines/reference/subtypingWithConstructSignatures6.js
+++ b/tests/baselines/reference/subtypingWithConstructSignatures6.js
@@ -57,8 +57,7 @@ interface I9<T> extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithNumericIndexer.js b/tests/baselines/reference/subtypingWithNumericIndexer.js
index a7790fba56..2ad6a2ebed 100644
--- a/tests/baselines/reference/subtypingWithNumericIndexer.js
+++ b/tests/baselines/reference/subtypingWithNumericIndexer.js
@@ -44,8 +44,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/subtypingWithNumericIndexer3.js b/tests/baselines/reference/subtypingWithNumericIndexer3.js
index c3fff86274..f4c2d1d9da 100644
--- a/tests/baselines/reference/subtypingWithNumericIndexer3.js
+++ b/tests/baselines/reference/subtypingWithNumericIndexer3.js
@@ -48,8 +48,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/subtypingWithNumericIndexer4.js b/tests/baselines/reference/subtypingWithNumericIndexer4.js
index e7ec08436a..7956464d17 100644
--- a/tests/baselines/reference/subtypingWithNumericIndexer4.js
+++ b/tests/baselines/reference/subtypingWithNumericIndexer4.js
@@ -32,8 +32,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/subtypingWithObjectMembers.js b/tests/baselines/reference/subtypingWithObjectMembers.js
index 28af723922..fc452ba8cf 100644
--- a/tests/baselines/reference/subtypingWithObjectMembers.js
+++ b/tests/baselines/reference/subtypingWithObjectMembers.js
@@ -71,8 +71,7 @@ module TwoLevels {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithObjectMembers4.js b/tests/baselines/reference/subtypingWithObjectMembers4.js
index b04c3056a3..487a5969f7 100644
--- a/tests/baselines/reference/subtypingWithObjectMembers4.js
+++ b/tests/baselines/reference/subtypingWithObjectMembers4.js
@@ -38,8 +38,7 @@ class B3 extends A3 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithObjectMembersAccessibility.js b/tests/baselines/reference/subtypingWithObjectMembersAccessibility.js
index d3b6289085..f08f2367d2 100644
--- a/tests/baselines/reference/subtypingWithObjectMembersAccessibility.js
+++ b/tests/baselines/reference/subtypingWithObjectMembersAccessibility.js
@@ -38,8 +38,7 @@ class B3 extends A3 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithObjectMembersAccessibility2.js b/tests/baselines/reference/subtypingWithObjectMembersAccessibility2.js
index 4a0ff448b7..c23405cd50 100644
--- a/tests/baselines/reference/subtypingWithObjectMembersAccessibility2.js
+++ b/tests/baselines/reference/subtypingWithObjectMembersAccessibility2.js
@@ -66,8 +66,7 @@ module ImplicitPublic {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/subtypingWithStringIndexer.js b/tests/baselines/reference/subtypingWithStringIndexer.js
index 4b398451de..5f606520a6 100644
--- a/tests/baselines/reference/subtypingWithStringIndexer.js
+++ b/tests/baselines/reference/subtypingWithStringIndexer.js
@@ -45,8 +45,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/subtypingWithStringIndexer3.js b/tests/baselines/reference/subtypingWithStringIndexer3.js
index cf1ec80a8d..6ce66c4e72 100644
--- a/tests/baselines/reference/subtypingWithStringIndexer3.js
+++ b/tests/baselines/reference/subtypingWithStringIndexer3.js
@@ -48,8 +48,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/subtypingWithStringIndexer4.js b/tests/baselines/reference/subtypingWithStringIndexer4.js
index e6aa298fed..19d36e475c 100644
--- a/tests/baselines/reference/subtypingWithStringIndexer4.js
+++ b/tests/baselines/reference/subtypingWithStringIndexer4.js
@@ -32,8 +32,7 @@ module Generics {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/super.js b/tests/baselines/reference/super.js
index ed220ae1f1..a6b698413e 100644
--- a/tests/baselines/reference/super.js
+++ b/tests/baselines/reference/super.js
@@ -41,8 +41,7 @@ s.foo() + ss.foo();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/super1.js b/tests/baselines/reference/super1.js
index 1bf75783a6..6a52cfcd9e 100644
--- a/tests/baselines/reference/super1.js
+++ b/tests/baselines/reference/super1.js
@@ -70,8 +70,7 @@ module Base4 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // Case 1
 var Base1 = (function () {
diff --git a/tests/baselines/reference/super2.js b/tests/baselines/reference/super2.js
index 0f5531a8d5..9d865194a2 100644
--- a/tests/baselines/reference/super2.js
+++ b/tests/baselines/reference/super2.js
@@ -54,8 +54,7 @@ results1.x() + results1.y() + results2.y();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // Case 5
 var Base5 = (function () {
diff --git a/tests/baselines/reference/superAccess.js b/tests/baselines/reference/superAccess.js
index bf6a9ee3ad..bb5a71a0b8 100644
--- a/tests/baselines/reference/superAccess.js
+++ b/tests/baselines/reference/superAccess.js
@@ -17,8 +17,7 @@ class MyDerived extends MyBase {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var MyBase = (function () {
     function MyBase() {
diff --git a/tests/baselines/reference/superAccess2.js b/tests/baselines/reference/superAccess2.js
index afcba34aa5..fd20f424ba 100644
--- a/tests/baselines/reference/superAccess2.js
+++ b/tests/baselines/reference/superAccess2.js
@@ -28,8 +28,7 @@ class Q extends P {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var P = (function () {
     function P() {
diff --git a/tests/baselines/reference/superAccessInFatArrow1.js b/tests/baselines/reference/superAccessInFatArrow1.js
index 6222bf42fe..0dc69179c9 100644
--- a/tests/baselines/reference/superAccessInFatArrow1.js
+++ b/tests/baselines/reference/superAccessInFatArrow1.js
@@ -19,8 +19,7 @@ module test {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var test;
 (function (test) {
diff --git a/tests/baselines/reference/superCallArgsMustMatch.js b/tests/baselines/reference/superCallArgsMustMatch.js
index 7c7948cc38..3369cf7e8d 100644
--- a/tests/baselines/reference/superCallArgsMustMatch.js
+++ b/tests/baselines/reference/superCallArgsMustMatch.js
@@ -29,8 +29,7 @@ class T6 extends T5<number>{
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var T5 = (function () {
     function T5(bar) {
diff --git a/tests/baselines/reference/superCallAssignResult.js b/tests/baselines/reference/superCallAssignResult.js
index a83e5b3de7..24a198e342 100644
--- a/tests/baselines/reference/superCallAssignResult.js
+++ b/tests/baselines/reference/superCallAssignResult.js
@@ -14,8 +14,7 @@ class H extends E {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var E = (function () {
     function E(arg) {
diff --git a/tests/baselines/reference/superCallFromClassThatDerivesFromGenericType1.js b/tests/baselines/reference/superCallFromClassThatDerivesFromGenericType1.js
index 15e26b5481..d59f6f5a57 100644
--- a/tests/baselines/reference/superCallFromClassThatDerivesFromGenericType1.js
+++ b/tests/baselines/reference/superCallFromClassThatDerivesFromGenericType1.js
@@ -15,8 +15,7 @@ class D extends B<any> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var D = (function (_super) {
     __extends(D, _super);
diff --git a/tests/baselines/reference/superCallFromClassThatDerivesFromGenericType2.js b/tests/baselines/reference/superCallFromClassThatDerivesFromGenericType2.js
index 15d24015a0..a3d5d42c82 100644
--- a/tests/baselines/reference/superCallFromClassThatDerivesFromGenericType2.js
+++ b/tests/baselines/reference/superCallFromClassThatDerivesFromGenericType2.js
@@ -14,8 +14,7 @@ class D extends B<any> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var D = (function (_super) {
     __extends(D, _super);
diff --git a/tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.js b/tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.js
index 114505b85a..155258861b 100644
--- a/tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.js
+++ b/tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithIncorrectNumberOfTypeArguments1.js
@@ -14,8 +14,7 @@ class B extends A<number> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(map) {
diff --git a/tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.js b/tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.js
index 226665e3e6..37883b9921 100644
--- a/tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.js
+++ b/tests/baselines/reference/superCallFromClassThatDerivesFromGenericTypeButWithNoTypeArguments1.js
@@ -14,8 +14,7 @@ class B extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(map) {
diff --git a/tests/baselines/reference/superCallFromClassThatDerivesNonGenericTypeButWithTypeArguments1.js b/tests/baselines/reference/superCallFromClassThatDerivesNonGenericTypeButWithTypeArguments1.js
index 7c07e78b0f..dbd4528c39 100644
--- a/tests/baselines/reference/superCallFromClassThatDerivesNonGenericTypeButWithTypeArguments1.js
+++ b/tests/baselines/reference/superCallFromClassThatDerivesNonGenericTypeButWithTypeArguments1.js
@@ -14,8 +14,7 @@ class B extends A<number, string> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(map) {
diff --git a/tests/baselines/reference/superCallInNonStaticMethod.js b/tests/baselines/reference/superCallInNonStaticMethod.js
index c3038e23c4..7de6a10045 100644
--- a/tests/baselines/reference/superCallInNonStaticMethod.js
+++ b/tests/baselines/reference/superCallInNonStaticMethod.js
@@ -54,8 +54,7 @@ class Other extends Doing {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Doing = (function () {
     function Doing() {
diff --git a/tests/baselines/reference/superCallInStaticMethod.js b/tests/baselines/reference/superCallInStaticMethod.js
index 7e57cd2d2e..9978773739 100644
--- a/tests/baselines/reference/superCallInStaticMethod.js
+++ b/tests/baselines/reference/superCallInStaticMethod.js
@@ -50,8 +50,7 @@ class Other extends Doing {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Doing = (function () {
     function Doing() {
diff --git a/tests/baselines/reference/superCallOutsideConstructor.js b/tests/baselines/reference/superCallOutsideConstructor.js
index 0a1822bc54..c2152e13db 100644
--- a/tests/baselines/reference/superCallOutsideConstructor.js
+++ b/tests/baselines/reference/superCallOutsideConstructor.js
@@ -26,8 +26,7 @@ var d = new D();
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/superCallParameterContextualTyping1.js b/tests/baselines/reference/superCallParameterContextualTyping1.js
index 4888473319..b7508e4cd7 100644
--- a/tests/baselines/reference/superCallParameterContextualTyping1.js
+++ b/tests/baselines/reference/superCallParameterContextualTyping1.js
@@ -16,8 +16,7 @@ class B extends A<number, string> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(map) {
diff --git a/tests/baselines/reference/superCallParameterContextualTyping2.js b/tests/baselines/reference/superCallParameterContextualTyping2.js
index ab6093c42b..996e0374c7 100644
--- a/tests/baselines/reference/superCallParameterContextualTyping2.js
+++ b/tests/baselines/reference/superCallParameterContextualTyping2.js
@@ -15,8 +15,7 @@ class C extends A<number, string> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(map) {
diff --git a/tests/baselines/reference/superCallParameterContextualTyping3.js b/tests/baselines/reference/superCallParameterContextualTyping3.js
index 574d281ed0..6f1311e58a 100644
--- a/tests/baselines/reference/superCallParameterContextualTyping3.js
+++ b/tests/baselines/reference/superCallParameterContextualTyping3.js
@@ -35,8 +35,7 @@ class C extends CBase<string> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var CBase = (function () {
     function CBase(param) {
diff --git a/tests/baselines/reference/superCalls.js b/tests/baselines/reference/superCalls.js
index d2e4f9ff7f..bd54ba34b5 100644
--- a/tests/baselines/reference/superCalls.js
+++ b/tests/baselines/reference/superCalls.js
@@ -34,8 +34,7 @@ class OtherDerived extends OtherBase {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(n) {
diff --git a/tests/baselines/reference/superCallsInConstructor.js b/tests/baselines/reference/superCallsInConstructor.js
index 6bd313898d..c238808b95 100644
--- a/tests/baselines/reference/superCallsInConstructor.js
+++ b/tests/baselines/reference/superCallsInConstructor.js
@@ -24,8 +24,7 @@ class Derived extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/superErrors.js b/tests/baselines/reference/superErrors.js
index 2e1cd346cd..3a3de50912 100644
--- a/tests/baselines/reference/superErrors.js
+++ b/tests/baselines/reference/superErrors.js
@@ -55,8 +55,7 @@ class RegisteredUser extends User {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function foo() {
     // super in a non class context
diff --git a/tests/baselines/reference/superInCatchBlock1.js b/tests/baselines/reference/superInCatchBlock1.js
index 38131f5f08..cf4c69c7b6 100644
--- a/tests/baselines/reference/superInCatchBlock1.js
+++ b/tests/baselines/reference/superInCatchBlock1.js
@@ -17,8 +17,7 @@ class B extends A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/superInConstructorParam1.js b/tests/baselines/reference/superInConstructorParam1.js
index aaf4162e99..7c0cc7bf40 100644
--- a/tests/baselines/reference/superInConstructorParam1.js
+++ b/tests/baselines/reference/superInConstructorParam1.js
@@ -14,8 +14,7 @@ class C extends B {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var B = (function () {
     function B() {
diff --git a/tests/baselines/reference/superInLambdas.js b/tests/baselines/reference/superInLambdas.js
index 5640425f6b..89d5798f88 100644
--- a/tests/baselines/reference/superInLambdas.js
+++ b/tests/baselines/reference/superInLambdas.js
@@ -71,8 +71,7 @@ class RegisteredUser4 extends User {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var User = (function () {
     function User() {
diff --git a/tests/baselines/reference/superNewCall1.js b/tests/baselines/reference/superNewCall1.js
index 1b11b61ce2..aa25e65e14 100644
--- a/tests/baselines/reference/superNewCall1.js
+++ b/tests/baselines/reference/superNewCall1.js
@@ -16,8 +16,7 @@ class B extends A<number, string> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A(map) {
diff --git a/tests/baselines/reference/superPropertyAccess.js b/tests/baselines/reference/superPropertyAccess.js
index 016fc09ff9..95dbb2f94e 100644
--- a/tests/baselines/reference/superPropertyAccess.js
+++ b/tests/baselines/reference/superPropertyAccess.js
@@ -40,8 +40,7 @@ class MyDerived extends MyBase {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var MyBase = (function () {
     function MyBase() {
diff --git a/tests/baselines/reference/superPropertyAccess1.js b/tests/baselines/reference/superPropertyAccess1.js
index 1ee834f349..748331af95 100644
--- a/tests/baselines/reference/superPropertyAccess1.js
+++ b/tests/baselines/reference/superPropertyAccess1.js
@@ -31,8 +31,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/superPropertyAccess2.js b/tests/baselines/reference/superPropertyAccess2.js
index 0877cf23b9..dccd4717ee 100644
--- a/tests/baselines/reference/superPropertyAccess2.js
+++ b/tests/baselines/reference/superPropertyAccess2.js
@@ -31,8 +31,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/superPropertyAccessNoError.js b/tests/baselines/reference/superPropertyAccessNoError.js
index f8ee7f6d01..44a6910a38 100644
--- a/tests/baselines/reference/superPropertyAccessNoError.js
+++ b/tests/baselines/reference/superPropertyAccessNoError.js
@@ -70,8 +70,7 @@ class SomeDerivedClass extends SomeBaseClass {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var SomeBaseClass = (function () {
     function SomeBaseClass() {
diff --git a/tests/baselines/reference/superWithGenericSpecialization.js b/tests/baselines/reference/superWithGenericSpecialization.js
index 5cd85f9073..3d1ea0f77a 100644
--- a/tests/baselines/reference/superWithGenericSpecialization.js
+++ b/tests/baselines/reference/superWithGenericSpecialization.js
@@ -18,8 +18,7 @@ var r2: number = d.y;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/superWithGenerics.js b/tests/baselines/reference/superWithGenerics.js
index 8ba6f878dc..482c7ba069 100644
--- a/tests/baselines/reference/superWithGenerics.js
+++ b/tests/baselines/reference/superWithGenerics.js
@@ -15,8 +15,7 @@ class D extends B<any> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var D = (function (_super) {
     __extends(D, _super);
diff --git a/tests/baselines/reference/superWithTypeArgument.js b/tests/baselines/reference/superWithTypeArgument.js
index 2e5ea93a47..6d5690cd68 100644
--- a/tests/baselines/reference/superWithTypeArgument.js
+++ b/tests/baselines/reference/superWithTypeArgument.js
@@ -13,8 +13,7 @@ class D<T> extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/superWithTypeArgument2.js b/tests/baselines/reference/superWithTypeArgument2.js
index c33497d58f..588094cd86 100644
--- a/tests/baselines/reference/superWithTypeArgument2.js
+++ b/tests/baselines/reference/superWithTypeArgument2.js
@@ -13,8 +13,7 @@ class D<T> extends C<T> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/superWithTypeArgument3.js b/tests/baselines/reference/superWithTypeArgument3.js
index 1266d97f26..8f0ba6c086 100644
--- a/tests/baselines/reference/superWithTypeArgument3.js
+++ b/tests/baselines/reference/superWithTypeArgument3.js
@@ -17,8 +17,7 @@ class D<T> extends C<T> {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/super_inside-object-literal-getters-and-setters.js b/tests/baselines/reference/super_inside-object-literal-getters-and-setters.js
index 97fa57528c..d2f240b766 100644
--- a/tests/baselines/reference/super_inside-object-literal-getters-and-setters.js
+++ b/tests/baselines/reference/super_inside-object-literal-getters-and-setters.js
@@ -31,8 +31,7 @@ class SuperObjectTest extends F {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var ObjectLiteral;
 (function (ObjectLiteral) {
diff --git a/tests/baselines/reference/switchStatements.js b/tests/baselines/reference/switchStatements.js
index debd9a4d53..39a4b2c901 100644
--- a/tests/baselines/reference/switchStatements.js
+++ b/tests/baselines/reference/switchStatements.js
@@ -59,8 +59,7 @@ switch ((<T>(x: T) => '')(1)) { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/targetTypeBaseCalls.js b/tests/baselines/reference/targetTypeBaseCalls.js
index bde689ba2c..41673a62ef 100644
--- a/tests/baselines/reference/targetTypeBaseCalls.js
+++ b/tests/baselines/reference/targetTypeBaseCalls.js
@@ -22,8 +22,7 @@ class Bar extends Foo { constructor() { super(function(s) { s = 5 }) } }  // err
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function foo(x) { }
 var Foo = (function () {
diff --git a/tests/baselines/reference/thisInInvalidContexts.js b/tests/baselines/reference/thisInInvalidContexts.js
index afce4ec037..84b9640468 100644
--- a/tests/baselines/reference/thisInInvalidContexts.js
+++ b/tests/baselines/reference/thisInInvalidContexts.js
@@ -52,8 +52,7 @@ enum SomeEnum {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 //'this' in static member initializer
 var ErrClass1 = (function () {
diff --git a/tests/baselines/reference/thisInInvalidContextsExternalModule.js b/tests/baselines/reference/thisInInvalidContextsExternalModule.js
index 8fcbe22643..7de94be942 100644
--- a/tests/baselines/reference/thisInInvalidContextsExternalModule.js
+++ b/tests/baselines/reference/thisInInvalidContextsExternalModule.js
@@ -52,8 +52,7 @@ export = this; // Should be an error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 //'this' in static member initializer
 var ErrClass1 = (function () {
diff --git a/tests/baselines/reference/thisInSuperCall.js b/tests/baselines/reference/thisInSuperCall.js
index 3da6d9c8a6..f7d7ca4e4f 100644
--- a/tests/baselines/reference/thisInSuperCall.js
+++ b/tests/baselines/reference/thisInSuperCall.js
@@ -26,8 +26,7 @@ class Foo3 extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(x) {
diff --git a/tests/baselines/reference/thisInSuperCall1.js b/tests/baselines/reference/thisInSuperCall1.js
index b0ff1bd4ba..4ae43784fe 100644
--- a/tests/baselines/reference/thisInSuperCall1.js
+++ b/tests/baselines/reference/thisInSuperCall1.js
@@ -14,8 +14,7 @@ class Foo extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(a) {
diff --git a/tests/baselines/reference/thisInSuperCall2.js b/tests/baselines/reference/thisInSuperCall2.js
index fca671a2c7..a9bbeda9fe 100644
--- a/tests/baselines/reference/thisInSuperCall2.js
+++ b/tests/baselines/reference/thisInSuperCall2.js
@@ -23,8 +23,7 @@ class Foo2 extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(a) {
diff --git a/tests/baselines/reference/thisInSuperCall3.js b/tests/baselines/reference/thisInSuperCall3.js
index fe2bdec77e..ba27add2d9 100644
--- a/tests/baselines/reference/thisInSuperCall3.js
+++ b/tests/baselines/reference/thisInSuperCall3.js
@@ -16,8 +16,7 @@ class Foo extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(a) {
diff --git a/tests/baselines/reference/typeAssertions.js b/tests/baselines/reference/typeAssertions.js
index 51ca6a27f0..3645e61f2b 100644
--- a/tests/baselines/reference/typeAssertions.js
+++ b/tests/baselines/reference/typeAssertions.js
@@ -46,8 +46,7 @@ someOther = <SomeOther>someOther;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // Function call whose argument is a 1 arg generic function call with explicit type arguments
 function fn1(t) { }
diff --git a/tests/baselines/reference/typeGuardFunction.js b/tests/baselines/reference/typeGuardFunction.js
index f6b752c8c0..bff304682a 100644
--- a/tests/baselines/reference/typeGuardFunction.js
+++ b/tests/baselines/reference/typeGuardFunction.js
@@ -87,8 +87,7 @@ let union3: boolean | B = isA(union2) || union2;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/typeGuardFunctionErrors.js b/tests/baselines/reference/typeGuardFunctionErrors.js
index 179a3b80cf..5b0979ac57 100644
--- a/tests/baselines/reference/typeGuardFunctionErrors.js
+++ b/tests/baselines/reference/typeGuardFunctionErrors.js
@@ -139,8 +139,7 @@ function b7({a, b, c: {p1}}, p2, p3): p1 is A {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/typeGuardFunctionGenerics.js b/tests/baselines/reference/typeGuardFunctionGenerics.js
index 6704225a0d..edf5cb97fe 100644
--- a/tests/baselines/reference/typeGuardFunctionGenerics.js
+++ b/tests/baselines/reference/typeGuardFunctionGenerics.js
@@ -37,8 +37,7 @@ let test3: B = funE(isB, 1);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var A = (function () {
     function A() {
diff --git a/tests/baselines/reference/typeGuardOfFormInstanceOf.js b/tests/baselines/reference/typeGuardOfFormInstanceOf.js
index de7e9813a8..cab04365c1 100644
--- a/tests/baselines/reference/typeGuardOfFormInstanceOf.js
+++ b/tests/baselines/reference/typeGuardOfFormInstanceOf.js
@@ -39,8 +39,7 @@ var r2: D1 | C2 = c2Ord1 instanceof C1 && c2Ord1; // C2 | D1
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1() {
diff --git a/tests/baselines/reference/typeGuardOfFormIsType.js b/tests/baselines/reference/typeGuardOfFormIsType.js
index 65d99319d1..8400aef59a 100644
--- a/tests/baselines/reference/typeGuardOfFormIsType.js
+++ b/tests/baselines/reference/typeGuardOfFormIsType.js
@@ -41,8 +41,7 @@ var r2: C2 | D1 = isC1(c2Ord1) && c2Ord1; // C2 | D1
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C1 = (function () {
     function C1() {
diff --git a/tests/baselines/reference/typeMatch2.js b/tests/baselines/reference/typeMatch2.js
index 6f05bf684f..c4550750ca 100644
--- a/tests/baselines/reference/typeMatch2.js
+++ b/tests/baselines/reference/typeMatch2.js
@@ -48,8 +48,7 @@ function f4() {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 function f1() {
     var a = { x: 1, y: 2 };
diff --git a/tests/baselines/reference/typeOfSuperCall.js b/tests/baselines/reference/typeOfSuperCall.js
index 5df29d615e..72cdd7d528 100644
--- a/tests/baselines/reference/typeOfSuperCall.js
+++ b/tests/baselines/reference/typeOfSuperCall.js
@@ -12,8 +12,7 @@ class D extends C {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C() {
diff --git a/tests/baselines/reference/typeParameterAsBaseClass.js b/tests/baselines/reference/typeParameterAsBaseClass.js
index b00a00abac..f17db28f65 100644
--- a/tests/baselines/reference/typeParameterAsBaseClass.js
+++ b/tests/baselines/reference/typeParameterAsBaseClass.js
@@ -6,8 +6,7 @@ class C2<T> implements T {}
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/typeParameterAsBaseType.js b/tests/baselines/reference/typeParameterAsBaseType.js
index 2715c09fa2..de9a0ed258 100644
--- a/tests/baselines/reference/typeParameterAsBaseType.js
+++ b/tests/baselines/reference/typeParameterAsBaseType.js
@@ -16,8 +16,7 @@ interface I2<T, U> extends U { }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function (_super) {
     __extends(C, _super);
diff --git a/tests/baselines/reference/typeParameterExtendingUnion1.js b/tests/baselines/reference/typeParameterExtendingUnion1.js
index c5e8fccf35..3027f119fb 100644
--- a/tests/baselines/reference/typeParameterExtendingUnion1.js
+++ b/tests/baselines/reference/typeParameterExtendingUnion1.js
@@ -16,8 +16,7 @@ function f<T extends Cat | Dog>(a: T) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Animal = (function () {
     function Animal() {
diff --git a/tests/baselines/reference/typeParameterExtendingUnion2.js b/tests/baselines/reference/typeParameterExtendingUnion2.js
index e53aeb42f2..55f6d3e07e 100644
--- a/tests/baselines/reference/typeParameterExtendingUnion2.js
+++ b/tests/baselines/reference/typeParameterExtendingUnion2.js
@@ -16,8 +16,7 @@ function f<T extends Cat | Dog>(a: T) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Animal = (function () {
     function Animal() {
diff --git a/tests/baselines/reference/typeValueConflict1.js b/tests/baselines/reference/typeValueConflict1.js
index d036d90262..0a6e92d0d6 100644
--- a/tests/baselines/reference/typeValueConflict1.js
+++ b/tests/baselines/reference/typeValueConflict1.js
@@ -15,8 +15,7 @@ module M2 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M1;
 (function (M1) {
diff --git a/tests/baselines/reference/typeValueConflict2.js b/tests/baselines/reference/typeValueConflict2.js
index c927e70615..6e925b535a 100644
--- a/tests/baselines/reference/typeValueConflict2.js
+++ b/tests/baselines/reference/typeValueConflict2.js
@@ -22,8 +22,7 @@ module M3 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M1;
 (function (M1) {
diff --git a/tests/baselines/reference/typeofClass2.js b/tests/baselines/reference/typeofClass2.js
index f4401db154..d16abbda6e 100644
--- a/tests/baselines/reference/typeofClass2.js
+++ b/tests/baselines/reference/typeofClass2.js
@@ -25,8 +25,7 @@ var r2: typeof d;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var C = (function () {
     function C(x) {
diff --git a/tests/baselines/reference/typesWithSpecializedCallSignatures.js b/tests/baselines/reference/typesWithSpecializedCallSignatures.js
index 4baa9d7119..3de4134789 100644
--- a/tests/baselines/reference/typesWithSpecializedCallSignatures.js
+++ b/tests/baselines/reference/typesWithSpecializedCallSignatures.js
@@ -46,8 +46,7 @@ var r3: Base = c.foo('hm');
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/typesWithSpecializedConstructSignatures.js b/tests/baselines/reference/typesWithSpecializedConstructSignatures.js
index 8f64b4be3b..c66c471b3a 100644
--- a/tests/baselines/reference/typesWithSpecializedConstructSignatures.js
+++ b/tests/baselines/reference/typesWithSpecializedConstructSignatures.js
@@ -44,8 +44,7 @@ var r3: Base = new a('hm');
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/undeclaredBase.js b/tests/baselines/reference/undeclaredBase.js
index bb78d5995c..b1efffc0e2 100644
--- a/tests/baselines/reference/undeclaredBase.js
+++ b/tests/baselines/reference/undeclaredBase.js
@@ -7,8 +7,7 @@ module M { export class C extends M.I { } }
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var M;
 (function (M) {
diff --git a/tests/baselines/reference/undefinedIsSubtypeOfEverything.js b/tests/baselines/reference/undefinedIsSubtypeOfEverything.js
index 49877eb62e..c89c3f6538 100644
--- a/tests/baselines/reference/undefinedIsSubtypeOfEverything.js
+++ b/tests/baselines/reference/undefinedIsSubtypeOfEverything.js
@@ -126,8 +126,7 @@ class D17 extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base() {
diff --git a/tests/baselines/reference/underscoreMapFirst.js b/tests/baselines/reference/underscoreMapFirst.js
index c1839fadfd..4ee69572f1 100644
--- a/tests/baselines/reference/underscoreMapFirst.js
+++ b/tests/baselines/reference/underscoreMapFirst.js
@@ -52,8 +52,7 @@ class MyView extends View {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var MyView = (function (_super) {
     __extends(MyView, _super);
diff --git a/tests/baselines/reference/unionTypeEquivalence.js b/tests/baselines/reference/unionTypeEquivalence.js
index 04ee64b73e..3f4ad647dd 100644
--- a/tests/baselines/reference/unionTypeEquivalence.js
+++ b/tests/baselines/reference/unionTypeEquivalence.js
@@ -23,8 +23,7 @@ var z1: string | typeof BC;
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // A | B is equivalent to A if B is a subtype of A
 var C = (function () {
diff --git a/tests/baselines/reference/unionTypeFromArrayLiteral.js b/tests/baselines/reference/unionTypeFromArrayLiteral.js
index ab43a6273b..1bfadd68ca 100644
--- a/tests/baselines/reference/unionTypeFromArrayLiteral.js
+++ b/tests/baselines/reference/unionTypeFromArrayLiteral.js
@@ -31,8 +31,7 @@ var arr9 = [e, f]; // (E|F)[]
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var arr1 = [1, 2]; // number[]
 var arr2 = ["hello", true]; // (string | number)[]
diff --git a/tests/baselines/reference/unionTypesAssignability.js b/tests/baselines/reference/unionTypesAssignability.js
index 7778e1bede..80eafb4f50 100644
--- a/tests/baselines/reference/unionTypesAssignability.js
+++ b/tests/baselines/reference/unionTypesAssignability.js
@@ -76,8 +76,7 @@ function foo<T, U>(t: T, u: U) {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var unionNumberString;
 var C = (function () {
diff --git a/tests/baselines/reference/unknownSymbols1.js b/tests/baselines/reference/unknownSymbols1.js
index 0e081a66b8..cab42726c7 100644
--- a/tests/baselines/reference/unknownSymbols1.js
+++ b/tests/baselines/reference/unknownSymbols1.js
@@ -36,8 +36,7 @@ class C5 {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var x = asdf;
 var y;
diff --git a/tests/baselines/reference/unspecializedConstraints.js b/tests/baselines/reference/unspecializedConstraints.js
index df64daff2b..ed844f740b 100644
--- a/tests/baselines/reference/unspecializedConstraints.js
+++ b/tests/baselines/reference/unspecializedConstraints.js
@@ -157,8 +157,7 @@ module ts {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var ts;
 (function (ts) {
diff --git a/tests/baselines/reference/untypedFunctionCallsWithTypeParameters1.js b/tests/baselines/reference/untypedFunctionCallsWithTypeParameters1.js
index 8304aae576..2f2d4e87c4 100644
--- a/tests/baselines/reference/untypedFunctionCallsWithTypeParameters1.js
+++ b/tests/baselines/reference/untypedFunctionCallsWithTypeParameters1.js
@@ -47,8 +47,7 @@ c5<string>(1); // error
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 // none of these function calls should be allowed
 var x = function () { return; };
diff --git a/tests/baselines/reference/validUseOfThisInSuper.js b/tests/baselines/reference/validUseOfThisInSuper.js
index 6f2fc67d7e..4378d89ad4 100644
--- a/tests/baselines/reference/validUseOfThisInSuper.js
+++ b/tests/baselines/reference/validUseOfThisInSuper.js
@@ -13,8 +13,7 @@ class Super extends Base {
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var Base = (function () {
     function Base(b) {
diff --git a/tests/baselines/reference/varArgsOnConstructorTypes.js b/tests/baselines/reference/varArgsOnConstructorTypes.js
index 005ba55d76..c3daf0c100 100644
--- a/tests/baselines/reference/varArgsOnConstructorTypes.js
+++ b/tests/baselines/reference/varArgsOnConstructorTypes.js
@@ -28,8 +28,7 @@ reg.register(B);
 var __extends = (this && this.__extends) || function (d, b) {
     for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
     function __() { this.constructor = d; }
-    __.prototype = b.prototype;
-    d.prototype = new __();
+    d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 define(["require", "exports"], function (require, exports) {
     var A = (function () {

From c67eecde5da1b7196998a2a23e89a07d78b17655 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Tue, 16 Jun 2015 12:35:34 -0700
Subject: [PATCH 3/3] Accepting new baselines

---
 .../project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts       | 3 +++
 .../project/quotesInFileAndDirectoryNames/node/m'ain.d.ts      | 3 +++
 2 files changed, 6 insertions(+)
 create mode 100644 tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts
 create mode 100644 tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.d.ts

diff --git a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts
new file mode 100644
index 0000000000..d7b4c67d49
--- /dev/null
+++ b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/amd/m'ain.d.ts
@@ -0,0 +1,3 @@
+/// <reference path="li'b/class'A.d.ts" />
+declare class ClassC extends test.ClassA {
+}
diff --git a/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.d.ts b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.d.ts
new file mode 100644
index 0000000000..d7b4c67d49
--- /dev/null
+++ b/tests/baselines/reference/project/quotesInFileAndDirectoryNames/node/m'ain.d.ts
@@ -0,0 +1,3 @@
+/// <reference path="li'b/class'A.d.ts" />
+declare class ClassC extends test.ClassA {
+}