diff --git a/api_guard/dist/types/index.d.ts b/api_guard/dist/types/index.d.ts
index 02cf3faf91..7c8e7e2ec9 100644
--- a/api_guard/dist/types/index.d.ts
+++ b/api_guard/dist/types/index.d.ts
@@ -330,7 +330,7 @@ export declare type PartialObserver<T> = NextObserver<T> | ErrorObserver<T> | Co
 export declare function partition<T, A>(source: ObservableInput<T>, predicate: (this: A, value: T, index: number) => boolean, thisArg: A): [Observable<T>, Observable<T>];
 export declare function partition<T>(source: ObservableInput<T>, predicate: (value: T, index: number) => boolean): [Observable<T>, Observable<T>];
 
-export declare function pipe<T>(): UnaryFunction<T, T>;
+export declare function pipe(): typeof identity;
 export declare function pipe<T, A>(fn1: UnaryFunction<T, A>): UnaryFunction<T, A>;
 export declare function pipe<T, A, B>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>): UnaryFunction<T, B>;
 export declare function pipe<T, A, B, C>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>): UnaryFunction<T, C>;
diff --git a/spec-dtslint/util/pipe-spec.ts b/spec-dtslint/util/pipe-spec.ts
index b063348b47..f4d30d1279 100644
--- a/spec-dtslint/util/pipe-spec.ts
+++ b/spec-dtslint/util/pipe-spec.ts
@@ -22,7 +22,7 @@ function a<I extends string, O extends string>(input: I, output: O): UnaryFuncti
 }
 
 it('should infer unknown for no arguments', () => {
-  const o = pipe(); // $ExpectType UnaryFunction<unknown, unknown>
+  const o = pipe(); // $ExpectType <T>(x: T) => T
 });
 
 it('should infer for 1 argument', () => {
diff --git a/src/internal/util/pipe.ts b/src/internal/util/pipe.ts
index f9c2a724c9..f68ae42622 100644
--- a/src/internal/util/pipe.ts
+++ b/src/internal/util/pipe.ts
@@ -2,17 +2,73 @@ import { identity } from './identity';
 import { UnaryFunction } from '../types';
 
 /* tslint:disable:max-line-length */
-export function pipe<T>(): UnaryFunction<T, T>;
+export function pipe(): typeof identity;
 export function pipe<T, A>(fn1: UnaryFunction<T, A>): UnaryFunction<T, A>;
 export function pipe<T, A, B>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>): UnaryFunction<T, B>;
 export function pipe<T, A, B, C>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>): UnaryFunction<T, C>;
-export function pipe<T, A, B, C, D>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>, fn4: UnaryFunction<C, D>): UnaryFunction<T, D>;
-export function pipe<T, A, B, C, D, E>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>, fn4: UnaryFunction<C, D>, fn5: UnaryFunction<D, E>): UnaryFunction<T, E>;
-export function pipe<T, A, B, C, D, E, F>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>, fn4: UnaryFunction<C, D>, fn5: UnaryFunction<D, E>, fn6: UnaryFunction<E, F>): UnaryFunction<T, F>;
-export function pipe<T, A, B, C, D, E, F, G>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>, fn4: UnaryFunction<C, D>, fn5: UnaryFunction<D, E>, fn6: UnaryFunction<E, F>, fn7: UnaryFunction<F, G>): UnaryFunction<T, G>;
-export function pipe<T, A, B, C, D, E, F, G, H>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>, fn4: UnaryFunction<C, D>, fn5: UnaryFunction<D, E>, fn6: UnaryFunction<E, F>, fn7: UnaryFunction<F, G>, fn8: UnaryFunction<G, H>): UnaryFunction<T, H>;
-export function pipe<T, A, B, C, D, E, F, G, H, I>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>, fn4: UnaryFunction<C, D>, fn5: UnaryFunction<D, E>, fn6: UnaryFunction<E, F>, fn7: UnaryFunction<F, G>, fn8: UnaryFunction<G, H>, fn9: UnaryFunction<H, I>): UnaryFunction<T, I>;
-export function pipe<T, A, B, C, D, E, F, G, H, I>(fn1: UnaryFunction<T, A>, fn2: UnaryFunction<A, B>, fn3: UnaryFunction<B, C>, fn4: UnaryFunction<C, D>, fn5: UnaryFunction<D, E>, fn6: UnaryFunction<E, F>, fn7: UnaryFunction<F, G>, fn8: UnaryFunction<G, H>, fn9: UnaryFunction<H, I>, ...fns: UnaryFunction<any, any>[]): UnaryFunction<T, {}>;
+export function pipe<T, A, B, C, D>(
+  fn1: UnaryFunction<T, A>,
+  fn2: UnaryFunction<A, B>,
+  fn3: UnaryFunction<B, C>,
+  fn4: UnaryFunction<C, D>
+): UnaryFunction<T, D>;
+export function pipe<T, A, B, C, D, E>(
+  fn1: UnaryFunction<T, A>,
+  fn2: UnaryFunction<A, B>,
+  fn3: UnaryFunction<B, C>,
+  fn4: UnaryFunction<C, D>,
+  fn5: UnaryFunction<D, E>
+): UnaryFunction<T, E>;
+export function pipe<T, A, B, C, D, E, F>(
+  fn1: UnaryFunction<T, A>,
+  fn2: UnaryFunction<A, B>,
+  fn3: UnaryFunction<B, C>,
+  fn4: UnaryFunction<C, D>,
+  fn5: UnaryFunction<D, E>,
+  fn6: UnaryFunction<E, F>
+): UnaryFunction<T, F>;
+export function pipe<T, A, B, C, D, E, F, G>(
+  fn1: UnaryFunction<T, A>,
+  fn2: UnaryFunction<A, B>,
+  fn3: UnaryFunction<B, C>,
+  fn4: UnaryFunction<C, D>,
+  fn5: UnaryFunction<D, E>,
+  fn6: UnaryFunction<E, F>,
+  fn7: UnaryFunction<F, G>
+): UnaryFunction<T, G>;
+export function pipe<T, A, B, C, D, E, F, G, H>(
+  fn1: UnaryFunction<T, A>,
+  fn2: UnaryFunction<A, B>,
+  fn3: UnaryFunction<B, C>,
+  fn4: UnaryFunction<C, D>,
+  fn5: UnaryFunction<D, E>,
+  fn6: UnaryFunction<E, F>,
+  fn7: UnaryFunction<F, G>,
+  fn8: UnaryFunction<G, H>
+): UnaryFunction<T, H>;
+export function pipe<T, A, B, C, D, E, F, G, H, I>(
+  fn1: UnaryFunction<T, A>,
+  fn2: UnaryFunction<A, B>,
+  fn3: UnaryFunction<B, C>,
+  fn4: UnaryFunction<C, D>,
+  fn5: UnaryFunction<D, E>,
+  fn6: UnaryFunction<E, F>,
+  fn7: UnaryFunction<F, G>,
+  fn8: UnaryFunction<G, H>,
+  fn9: UnaryFunction<H, I>
+): UnaryFunction<T, I>;
+export function pipe<T, A, B, C, D, E, F, G, H, I>(
+  fn1: UnaryFunction<T, A>,
+  fn2: UnaryFunction<A, B>,
+  fn3: UnaryFunction<B, C>,
+  fn4: UnaryFunction<C, D>,
+  fn5: UnaryFunction<D, E>,
+  fn6: UnaryFunction<E, F>,
+  fn7: UnaryFunction<F, G>,
+  fn8: UnaryFunction<G, H>,
+  fn9: UnaryFunction<H, I>,
+  ...fns: UnaryFunction<any, any>[]
+): UnaryFunction<T, {}>;
 /* tslint:enable:max-line-length */
 
 export function pipe(...fns: Array<UnaryFunction<any, any>>): UnaryFunction<any, any> {