diff --git a/rx.js/rx.js.d.ts b/rx.js/rx.js.d.ts
index cda048cf14..7e4e1466f8 100644
--- a/rx.js/rx.js.d.ts
+++ b/rx.js/rx.js.d.ts
@@ -406,6 +406,7 @@ declare module Rx {
 		merge<T>(scheduler: IScheduler, sources: IObservable<T>[]): IObservable<T>;
 		onErrorResumeNext<T>(...sources: IObservable<T>[]): IObservable<T>;
 		onErrorResumeNext<T>(sources: IObservable<T>[]): IObservable<T>;
+		zip<TResult>(...soucesAndResultSelector: any[]): IObservable<TResult>;
 	}
 
 	var Observable: Observable;
@@ -456,4 +457,4 @@ declare module Rx {
 		onError(exception: any): void;
 		onCompleted(): void;
 	}
-}
\ No newline at end of file
+}