diff --git a/types/angular-material/index.d.ts b/types/angular-material/index.d.ts
index 62060c4cd1..56ec1474d2 100644
--- a/types/angular-material/index.d.ts
+++ b/types/angular-material/index.d.ts
@@ -346,7 +346,7 @@ declare module 'angular' {
         interface IMenuService {
             close(): void;
             hide(response?: any, options?: any): IPromise<any>;
-            open(event?: JQueryEventObject): void;
+            open(event?: MouseEvent | JQueryEventObject): void;
         }
 
         interface IColorPalette {