diff --git a/modules/@angular/common/src/pipes/async_pipe.ts b/modules/@angular/common/src/pipes/async_pipe.ts
index 59af55ab80..3c21fd13c0 100644
--- a/modules/@angular/common/src/pipes/async_pipe.ts
+++ b/modules/@angular/common/src/pipes/async_pipe.ts
@@ -82,6 +82,9 @@ export class AsyncPipe implements OnDestroy, PipeTransform {
     }
   }
 
+  transform<T>(obj: Observable<T>): T|null;
+  transform<T>(obj: Promise<T>): T|null;
+  transform<T>(obj: EventEmitter<T>): T|null;
   transform(obj: Observable<any>|Promise<any>|EventEmitter<any>): any {
     if (!this._obj) {
       if (obj) {
@@ -93,7 +96,7 @@ export class AsyncPipe implements OnDestroy, PipeTransform {
 
     if (obj !== this._obj) {
       this._dispose();
-      return this.transform(obj);
+      return this.transform(obj as any);
     }
 
     if (this._latestValue === this._latestReturnedValue) {
diff --git a/tools/public_api_guard/common/index.d.ts b/tools/public_api_guard/common/index.d.ts
index c86bbffa57..5a81a9b079 100644
--- a/tools/public_api_guard/common/index.d.ts
+++ b/tools/public_api_guard/common/index.d.ts
@@ -5,7 +5,9 @@ export declare const APP_BASE_HREF: InjectionToken<string>;
 export declare class AsyncPipe implements OnDestroy, PipeTransform {
     constructor(_ref: ChangeDetectorRef);
     ngOnDestroy(): void;
-    transform(obj: Observable<any> | Promise<any> | EventEmitter<any>): any;
+    transform<T>(obj: EventEmitter<T>): T | null;
+    transform<T>(obj: Promise<T>): T | null;
+    transform<T>(obj: Observable<T>): T | null;
 }
 
 /** @stable */