diff --git a/q/Q.d.ts b/q/Q.d.ts
index 617bf0140..90ec8b461 100644
--- a/q/Q.d.ts
+++ b/q/Q.d.ts
@@ -294,7 +294,10 @@ declare module Q {
      * Returns a promise that will have the same result as promise, but will only be fulfilled or rejected after at least ms milliseconds have passed.
      */
     export function delay<T>(value: T, ms: number): Promise<T>;
-
+    /**
+     * Returns a promise that will be fulfilled with undefined after at least ms milliseconds have passed.
+     */
+    export function delay(ms: number): Promise <void>;
     /**
      * Returns whether a given promise is in the fulfilled state. When the static version is used on non-promises, the result is always true.
      */