diff --git a/extensions/window-list/extension.js b/extensions/window-list/extension.js
index cd0a6d98..bc81c76a 100644
--- a/extensions/window-list/extension.js
+++ b/extensions/window-list/extension.js
@@ -77,7 +77,7 @@ class WindowContextMenu extends PopupMenu.PopupMenu {
             'notify::minimized', this._updateMinimizeItem.bind(this),
             'notify::maximized-horizontally', this._updateMaximizeItem.bind(this),
             'notify::maximized-vertically', this._updateMaximizeItem.bind(this),
-            this);
+            this.actor);
 
         this._updateMinimizeItem();
         this._updateMaximizeItem();