diff --git a/typescript/base/single/button/button.node.ts b/typescript/base/single/button/button.node.ts
index b783a7c9f..6c21e9b1a 100644
--- a/typescript/base/single/button/button.node.ts
+++ b/typescript/base/single/button/button.node.ts
@@ -1,7 +1,7 @@
 import { _BasicButton, BasicButton } from "./button.basic";
 
 export interface _NodeButton extends _BasicButton {
-    isOpened(): void;
+    isOpened(): boolean;
 
     setOpened(b: boolean): void;