diff --git a/bin/typescript.d.ts b/bin/typescript.d.ts
index 3ec7b1230a..7cf08879ea 100644
--- a/bin/typescript.d.ts
+++ b/bin/typescript.d.ts
@@ -1095,6 +1095,7 @@ declare module "typescript" {
         mapRoot?: string;
         module?: ModuleKind;
         noEmit?: boolean;
+        noEmitHelpers?: boolean;
         noEmitOnError?: boolean;
         noErrorTruncation?: boolean;
         noImplicitAny?: boolean;
diff --git a/bin/typescriptServices.d.ts b/bin/typescriptServices.d.ts
index 9b5072a058..92427e18f2 100644
--- a/bin/typescriptServices.d.ts
+++ b/bin/typescriptServices.d.ts
@@ -1095,6 +1095,7 @@ declare module ts {
         mapRoot?: string;
         module?: ModuleKind;
         noEmit?: boolean;
+        noEmitHelpers?: boolean;
         noEmitOnError?: boolean;
         noErrorTruncation?: boolean;
         noImplicitAny?: boolean;
diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 15a67db77e..da31878403 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -71,6 +71,10 @@ module ts {
             type: "boolean",
             description: Diagnostics.Do_not_emit_outputs,
         },
+        {
+            name: "noEmitHelpers",
+            type: "boolean"
+        },
         {
             name: "noEmitOnError",
             type: "boolean",
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 9e3e18b031..020952a765 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -5614,24 +5614,28 @@ var __param = (this && this.__param) || function (paramIndex, decorator) {
 
                 // emit prologue directives prior to __extends
                 var startIndex = emitDirectivePrologues(node.statements, /*startWithNewLine*/ false);
-                // Only Emit __extends function when target ES5.
-                // For target ES6 and above, we can emit classDeclaration as is.
-                if ((languageVersion < ScriptTarget.ES6) && (!extendsEmitted && resolver.getNodeCheckFlags(node) & NodeCheckFlags.EmitExtends)) {
-                    writeLines(extendsHelper);
-                    extendsEmitted = true;
-                }
 
-                if (!decorateEmitted && resolver.getNodeCheckFlags(node) & NodeCheckFlags.EmitDecorate) {
-                    writeLines(decorateHelper);
-                    if (compilerOptions.emitDecoratorMetadata) {
-                        writeLines(metadataHelper);
+                // Only emit helpers if the user did not say otherwise.
+                if (!compilerOptions.noEmitHelpers) {
+                    // Only Emit __extends function when target ES5.
+                    // For target ES6 and above, we can emit classDeclaration as is.
+                    if ((languageVersion < ScriptTarget.ES6) && (!extendsEmitted && resolver.getNodeCheckFlags(node) & NodeCheckFlags.EmitExtends)) {
+                        writeLines(extendsHelper);
+                        extendsEmitted = true;
                     }
-                    decorateEmitted = true;
-                }
 
-                if (!paramEmitted && resolver.getNodeCheckFlags(node) & NodeCheckFlags.EmitParam) {
-                    writeLines(paramHelper);
-                    paramEmitted = true;
+                    if (!decorateEmitted && resolver.getNodeCheckFlags(node) & NodeCheckFlags.EmitDecorate) {
+                        writeLines(decorateHelper);
+                        if (compilerOptions.emitDecoratorMetadata) {
+                            writeLines(metadataHelper);
+                        }
+                        decorateEmitted = true;
+                    }
+
+                    if (!paramEmitted && resolver.getNodeCheckFlags(node) & NodeCheckFlags.EmitParam) {
+                        writeLines(paramHelper);
+                        paramEmitted = true;
+                    }
                 }
 
                 if (isExternalModule(node) || compilerOptions.separateCompilation) {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 4799f31406..9e7e6ac732 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -1657,6 +1657,7 @@ module ts {
         mapRoot?: string;
         module?: ModuleKind;
         noEmit?: boolean;
+        noEmitHelpers?: boolean;
         noEmitOnError?: boolean;
         noErrorTruncation?: boolean;
         noImplicitAny?: boolean;
diff --git a/src/harness/harness.ts b/src/harness/harness.ts
index 6af77e3d74..30ae22a9e4 100644
--- a/src/harness/harness.ts
+++ b/src/harness/harness.ts
@@ -990,6 +990,14 @@ module Harness {
                             }
                             break;
 
+                        case 'emitdecoratormetadata':
+                            options.emitDecoratorMetadata = setting.value === 'true';
+                            break;
+
+                        case 'noemithelpers':
+                            options.noEmitHelpers = setting.value === 'true';
+                            break;
+
                         case 'noemitonerror':
                             options.noEmitOnError = !!setting.value;
                             break;
@@ -1477,12 +1485,12 @@ module Harness {
 
         // List of allowed metadata names
         var fileMetadataNames = ["filename", "comments", "declaration", "module",
-            "nolib", "sourcemap", "target", "out", "outdir", "noemitonerror",
+            "nolib", "sourcemap", "target", "out", "outdir", "noemithelpers", "noemitonerror",
             "noimplicitany", "noresolve", "newline", "newlines", "emitbom",
             "errortruncation", "usecasesensitivefilenames", "preserveconstenums",
             "includebuiltfile", "suppressimplicitanyindexerrors", "stripinternal",
             "separatecompilation", "inlinesourcemap", "maproot", "sourceroot",
-            "inlinesources"];
+            "inlinesources", "emitdecoratormetadata"];
 
         function extractCompilerSettings(content: string): CompilerSetting[] {
 
diff --git a/tests/baselines/reference/noEmitHelpers.js b/tests/baselines/reference/noEmitHelpers.js
new file mode 100644
index 0000000000..8db5cd862b
--- /dev/null
+++ b/tests/baselines/reference/noEmitHelpers.js
@@ -0,0 +1,19 @@
+//// [noEmitHelpers.ts]
+
+class A { }
+class B extends A { }
+
+
+//// [noEmitHelpers.js]
+var A = (function () {
+    function A() {
+    }
+    return A;
+})();
+var B = (function (_super) {
+    __extends(B, _super);
+    function B() {
+        _super.apply(this, arguments);
+    }
+    return B;
+})(A);
diff --git a/tests/baselines/reference/noEmitHelpers.symbols b/tests/baselines/reference/noEmitHelpers.symbols
new file mode 100644
index 0000000000..efd281c812
--- /dev/null
+++ b/tests/baselines/reference/noEmitHelpers.symbols
@@ -0,0 +1,9 @@
+=== tests/cases/compiler/noEmitHelpers.ts ===
+
+class A { }
+>A : Symbol(A, Decl(noEmitHelpers.ts, 0, 0))
+
+class B extends A { }
+>B : Symbol(B, Decl(noEmitHelpers.ts, 1, 11))
+>A : Symbol(A, Decl(noEmitHelpers.ts, 0, 0))
+
diff --git a/tests/baselines/reference/noEmitHelpers.types b/tests/baselines/reference/noEmitHelpers.types
new file mode 100644
index 0000000000..d25bd88255
--- /dev/null
+++ b/tests/baselines/reference/noEmitHelpers.types
@@ -0,0 +1,9 @@
+=== tests/cases/compiler/noEmitHelpers.ts ===
+
+class A { }
+>A : A
+
+class B extends A { }
+>B : B
+>A : A
+
diff --git a/tests/baselines/reference/noEmitHelpers2.js b/tests/baselines/reference/noEmitHelpers2.js
new file mode 100644
index 0000000000..1bd4237767
--- /dev/null
+++ b/tests/baselines/reference/noEmitHelpers2.js
@@ -0,0 +1,22 @@
+//// [noEmitHelpers2.ts]
+
+function decorator() { }
+
+@decorator
+class A {
+    constructor(a: number, @decorator b: string) {
+    }
+}
+
+//// [noEmitHelpers2.js]
+function decorator() { }
+var A = (function () {
+    function A(a, b) {
+    }
+    A = __decorate([
+        decorator,
+        __param(1, decorator), 
+        __metadata('design:paramtypes', [Number, String])
+    ], A);
+    return A;
+})();
diff --git a/tests/baselines/reference/noEmitHelpers2.symbols b/tests/baselines/reference/noEmitHelpers2.symbols
new file mode 100644
index 0000000000..3a3e3ec94c
--- /dev/null
+++ b/tests/baselines/reference/noEmitHelpers2.symbols
@@ -0,0 +1,17 @@
+=== tests/cases/compiler/noEmitHelpers2.ts ===
+
+function decorator() { }
+>decorator : Symbol(decorator, Decl(noEmitHelpers2.ts, 0, 0))
+
+@decorator
+>decorator : Symbol(decorator, Decl(noEmitHelpers2.ts, 0, 0))
+
+class A {
+>A : Symbol(A, Decl(noEmitHelpers2.ts, 1, 24))
+
+    constructor(a: number, @decorator b: string) {
+>a : Symbol(a, Decl(noEmitHelpers2.ts, 5, 16))
+>decorator : Symbol(decorator, Decl(noEmitHelpers2.ts, 0, 0))
+>b : Symbol(b, Decl(noEmitHelpers2.ts, 5, 26))
+    }
+}
diff --git a/tests/baselines/reference/noEmitHelpers2.types b/tests/baselines/reference/noEmitHelpers2.types
new file mode 100644
index 0000000000..2a5b5413a7
--- /dev/null
+++ b/tests/baselines/reference/noEmitHelpers2.types
@@ -0,0 +1,17 @@
+=== tests/cases/compiler/noEmitHelpers2.ts ===
+
+function decorator() { }
+>decorator : () => void
+
+@decorator
+>decorator : () => void
+
+class A {
+>A : A
+
+    constructor(a: number, @decorator b: string) {
+>a : number
+>decorator : () => void
+>b : string
+    }
+}
diff --git a/tests/cases/compiler/noEmitHelpers.ts b/tests/cases/compiler/noEmitHelpers.ts
new file mode 100644
index 0000000000..cb37c0db96
--- /dev/null
+++ b/tests/cases/compiler/noEmitHelpers.ts
@@ -0,0 +1,4 @@
+// @noemithelpers: true
+
+class A { }
+class B extends A { }
diff --git a/tests/cases/compiler/noEmitHelpers2.ts b/tests/cases/compiler/noEmitHelpers2.ts
new file mode 100644
index 0000000000..df71f4fae8
--- /dev/null
+++ b/tests/cases/compiler/noEmitHelpers2.ts
@@ -0,0 +1,11 @@
+// @noemithelpers: true
+// @emitdecoratormetadata: true
+// @target: es5
+
+function decorator() { }
+
+@decorator
+class A {
+    constructor(a: number, @decorator b: string) {
+    }
+}
\ No newline at end of file