diff --git a/src/lib/es2015.promise.d.ts b/src/lib/es2015.promise.d.ts
index 8ceb2cce1e..09bee735db 100644
--- a/src/lib/es2015.promise.d.ts
+++ b/src/lib/es2015.promise.d.ts
@@ -10,7 +10,7 @@ interface PromiseConstructor {
      * a resolve callback used resolve the promise with a value or the result of another promise,
      * and a reject callback used to reject the promise with a provided reason or error.
      */
-    new <T>(executor: (resolve: (value?: T | Awaitable<T>) => void, reject: (reason?: any) => void) => void): Promise<T>;
+    new <T>(executor: (resolve: (value?: T | PromiseLike<T>) => void, reject: (reason?: any) => void) => void): Promise<T>;
 
     /**
      * Creates a Promise that is resolved with an array of results when all of the provided Promises
diff --git a/src/lib/es5.d.ts b/src/lib/es5.d.ts
index 2cb954528c..6ef033dc33 100644
--- a/src/lib/es5.d.ts
+++ b/src/lib/es5.d.ts
@@ -1273,16 +1273,13 @@ declare type PropertyDecorator = (target: Object, propertyKey: string | symbol)
 declare type MethodDecorator = <T>(target: Object, propertyKey: string | symbol, descriptor: TypedPropertyDescriptor<T>) => TypedPropertyDescriptor<T> | void;
 declare type ParameterDecorator = (target: Object, propertyKey: string | symbol, parameterIndex: number) => void;
 
-/** An object type that can definitely be awaited. Do not inherit from this type. */
-declare type Awaitable<T> = { then(onfulfilled: (value: T) => any): any; };
-
 /** Gets the resulting type from awaiting `T`. This does **not** recursively unwrap nested promises. */
 declare type Awaited<T> =
-    T extends Awaitable<infer U> ? U :
+    T extends { then(onfulfilled: (value: infer U) => any): any; } ? U :
     T extends { then(...args: any[]): any; } ? never :
     T;
 
-declare type PromiseConstructorLike = new <T>(executor: (resolve: (value?: T | Awaitable<T>) => void, reject: (reason?: any) => void) => void) => PromiseLike<T>;
+declare type PromiseConstructorLike = new <T>(executor: (resolve: (value?: T | PromiseLike<T>) => void, reject: (reason?: any) => void) => void) => PromiseLike<T>;
 
 interface PromiseLike<T> {
     /**
diff --git a/tests/baselines/reference/asyncAwaitNestedClasses_es5.types b/tests/baselines/reference/asyncAwaitNestedClasses_es5.types
index 48c9576a74..fd61951d5c 100644
--- a/tests/baselines/reference/asyncAwaitNestedClasses_es5.types
+++ b/tests/baselines/reference/asyncAwaitNestedClasses_es5.types
@@ -15,10 +15,10 @@ class A {
             return new Promise((resolve) => { resolve(null); });
 >new Promise((resolve) => { resolve(null); }) : Promise<void>
 >Promise : PromiseConstructor
->(resolve) => { resolve(null); } : (resolve: (value?: void | Awaitable<void>) => void) => void
->resolve : (value?: void | Awaitable<void>) => void
+>(resolve) => { resolve(null); } : (resolve: (value?: void | PromiseLike<void>) => void) => void
+>resolve : (value?: void | PromiseLike<void>) => void
 >resolve(null) : void
->resolve : (value?: void | Awaitable<void>) => void
+>resolve : (value?: void | PromiseLike<void>) => void
 >null : null
         }
         static C = class C {
diff --git a/tests/baselines/reference/defaultExportInAwaitExpression01.types b/tests/baselines/reference/defaultExportInAwaitExpression01.types
index 469f07fb7d..1f7de76b90 100644
--- a/tests/baselines/reference/defaultExportInAwaitExpression01.types
+++ b/tests/baselines/reference/defaultExportInAwaitExpression01.types
@@ -3,11 +3,11 @@ const x = new Promise( ( resolve, reject ) => { resolve( {} ); } );
 >x : Promise<{}>
 >new Promise( ( resolve, reject ) => { resolve( {} ); } ) : Promise<{}>
 >Promise : PromiseConstructor
->( resolve, reject ) => { resolve( {} ); } : (resolve: (value?: {} | Awaitable<{}>) => void, reject: (reason?: any) => void) => void
->resolve : (value?: {} | Awaitable<{}>) => void
+>( resolve, reject ) => { resolve( {} ); } : (resolve: (value?: {} | PromiseLike<{}>) => void, reject: (reason?: any) => void) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >reject : (reason?: any) => void
 >resolve( {} ) : void
->resolve : (value?: {} | Awaitable<{}>) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >{} : {}
 
 export default x;
diff --git a/tests/baselines/reference/defaultExportInAwaitExpression02.types b/tests/baselines/reference/defaultExportInAwaitExpression02.types
index 469f07fb7d..1f7de76b90 100644
--- a/tests/baselines/reference/defaultExportInAwaitExpression02.types
+++ b/tests/baselines/reference/defaultExportInAwaitExpression02.types
@@ -3,11 +3,11 @@ const x = new Promise( ( resolve, reject ) => { resolve( {} ); } );
 >x : Promise<{}>
 >new Promise( ( resolve, reject ) => { resolve( {} ); } ) : Promise<{}>
 >Promise : PromiseConstructor
->( resolve, reject ) => { resolve( {} ); } : (resolve: (value?: {} | Awaitable<{}>) => void, reject: (reason?: any) => void) => void
->resolve : (value?: {} | Awaitable<{}>) => void
+>( resolve, reject ) => { resolve( {} ); } : (resolve: (value?: {} | PromiseLike<{}>) => void, reject: (reason?: any) => void) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >reject : (reason?: any) => void
 >resolve( {} ) : void
->resolve : (value?: {} | Awaitable<{}>) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >{} : {}
 
 export default x;
diff --git a/tests/baselines/reference/inferenceLimit.types b/tests/baselines/reference/inferenceLimit.types
index 0466182b59..d10f6d245d 100644
--- a/tests/baselines/reference/inferenceLimit.types
+++ b/tests/baselines/reference/inferenceLimit.types
@@ -21,8 +21,8 @@ export class BrokenClass {
 >Array : T[]
 >MyModule : any
 >MyModel : MyModule.MyModel
->(resolve, reject) => {    let result: Array<MyModule.MyModel> = [];    let populateItems = (order) => {      return new Promise((resolve, reject) => {        this.doStuff(order.id)          .then((items) => {            order.items = items;            resolve(order);          });      });    };    return Promise.all(result.map(populateItems))      .then((orders: Array<MyModule.MyModel>) => {        resolve(orders);      });    } : (resolve: (value?: MyModule.MyModel[] | Awaitable<MyModule.MyModel[]>) => void, reject: (reason?: any) => void) => Promise<void>
->resolve : (value?: MyModule.MyModel[] | Awaitable<MyModule.MyModel[]>) => void
+>(resolve, reject) => {    let result: Array<MyModule.MyModel> = [];    let populateItems = (order) => {      return new Promise((resolve, reject) => {        this.doStuff(order.id)          .then((items) => {            order.items = items;            resolve(order);          });      });    };    return Promise.all(result.map(populateItems))      .then((orders: Array<MyModule.MyModel>) => {        resolve(orders);      });    } : (resolve: (value?: MyModule.MyModel[] | PromiseLike<MyModule.MyModel[]>) => void, reject: (reason?: any) => void) => Promise<void>
+>resolve : (value?: MyModule.MyModel[] | PromiseLike<MyModule.MyModel[]>) => void
 >reject : (reason?: any) => void
 
     let result: Array<MyModule.MyModel> = [];
@@ -40,8 +40,8 @@ export class BrokenClass {
       return new Promise((resolve, reject) => {
 >new Promise((resolve, reject) => {        this.doStuff(order.id)          .then((items) => {            order.items = items;            resolve(order);          });      }) : Promise<{}>
 >Promise : PromiseConstructor
->(resolve, reject) => {        this.doStuff(order.id)          .then((items) => {            order.items = items;            resolve(order);          });      } : (resolve: (value?: {} | Awaitable<{}>) => void, reject: (reason?: any) => void) => void
->resolve : (value?: {} | Awaitable<{}>) => void
+>(resolve, reject) => {        this.doStuff(order.id)          .then((items) => {            order.items = items;            resolve(order);          });      } : (resolve: (value?: {} | PromiseLike<{}>) => void, reject: (reason?: any) => void) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >reject : (reason?: any) => void
 
         this.doStuff(order.id)
@@ -69,7 +69,7 @@ export class BrokenClass {
 
             resolve(order);
 >resolve(order) : void
->resolve : (value?: {} | Awaitable<{}>) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >order : any
 
           });
@@ -99,7 +99,7 @@ export class BrokenClass {
 
         resolve(orders);
 >resolve(orders) : void
->resolve : (value?: MyModule.MyModel[] | Awaitable<MyModule.MyModel[]>) => void
+>resolve : (value?: MyModule.MyModel[] | PromiseLike<MyModule.MyModel[]>) => void
 >orders : MyModule.MyModel[]
 
       });
diff --git a/tests/baselines/reference/modularizeLibrary_NoErrorDuplicateLibOptions1.types b/tests/baselines/reference/modularizeLibrary_NoErrorDuplicateLibOptions1.types
index 923f94f56c..b9c85e4bbd 100644
--- a/tests/baselines/reference/modularizeLibrary_NoErrorDuplicateLibOptions1.types
+++ b/tests/baselines/reference/modularizeLibrary_NoErrorDuplicateLibOptions1.types
@@ -137,8 +137,8 @@ async function out() {
     return new Promise(function (resolve, reject) {});
 >new Promise(function (resolve, reject) {}) : Promise<{}>
 >Promise : PromiseConstructor
->function (resolve, reject) {} : (resolve: (value?: {} | Awaitable<{}>) => void, reject: (reason?: any) => void) => void
->resolve : (value?: {} | Awaitable<{}>) => void
+>function (resolve, reject) {} : (resolve: (value?: {} | PromiseLike<{}>) => void, reject: (reason?: any) => void) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >reject : (reason?: any) => void
 }
 
diff --git a/tests/baselines/reference/modularizeLibrary_NoErrorDuplicateLibOptions2.types b/tests/baselines/reference/modularizeLibrary_NoErrorDuplicateLibOptions2.types
index c6e57aa4d5..bfea7b6ab3 100644
--- a/tests/baselines/reference/modularizeLibrary_NoErrorDuplicateLibOptions2.types
+++ b/tests/baselines/reference/modularizeLibrary_NoErrorDuplicateLibOptions2.types
@@ -137,8 +137,8 @@ async function out() {
     return new Promise(function (resolve, reject) {});
 >new Promise(function (resolve, reject) {}) : Promise<{}>
 >Promise : PromiseConstructor
->function (resolve, reject) {} : (resolve: (value?: {} | Awaitable<{}>) => void, reject: (reason?: any) => void) => void
->resolve : (value?: {} | Awaitable<{}>) => void
+>function (resolve, reject) {} : (resolve: (value?: {} | PromiseLike<{}>) => void, reject: (reason?: any) => void) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >reject : (reason?: any) => void
 }
 
diff --git a/tests/baselines/reference/modularizeLibrary_TargetES5UsingES6Lib.types b/tests/baselines/reference/modularizeLibrary_TargetES5UsingES6Lib.types
index 914ba4eaab..37eab2285d 100644
--- a/tests/baselines/reference/modularizeLibrary_TargetES5UsingES6Lib.types
+++ b/tests/baselines/reference/modularizeLibrary_TargetES5UsingES6Lib.types
@@ -137,8 +137,8 @@ async function out() {
     return new Promise(function (resolve, reject) {});
 >new Promise(function (resolve, reject) {}) : Promise<{}>
 >Promise : PromiseConstructor
->function (resolve, reject) {} : (resolve: (value?: {} | Awaitable<{}>) => void, reject: (reason?: any) => void) => void
->resolve : (value?: {} | Awaitable<{}>) => void
+>function (resolve, reject) {} : (resolve: (value?: {} | PromiseLike<{}>) => void, reject: (reason?: any) => void) => void
+>resolve : (value?: {} | PromiseLike<{}>) => void
 >reject : (reason?: any) => void
 }