diff --git a/src/app.js b/src/app.js
index f26a3c37..fe3f2e2c 100644
--- a/src/app.js
+++ b/src/app.js
@@ -48,6 +48,8 @@ class ClapperApp extends AppBase
         window.disconnect(this.mapSignal);
         this.mapSignal = null;
 
+        debug('window mapped');
+
         window.child._onWindowMap(window);
     }
 });