diff --git a/typescript/core/controller/controller.broadcast.ts b/typescript/core/controller/controller.broadcast.ts
index 3b5bf68e1..668bbc45a 100644
--- a/typescript/core/controller/controller.broadcast.ts
+++ b/typescript/core/controller/controller.broadcast.ts
@@ -5,5 +5,5 @@ export declare class BroadcastController extends Controller {
 
     send(name: string, ...args: any[]): void;
 
-    remove(name: string, fn: Function): this;
+    remove(name: string, fn?: Function): this;
 }