diff --git a/toonz/sources/toonz/sceneviewer.cpp b/toonz/sources/toonz/sceneviewer.cpp
index f00b9c8..6926f00 100644
--- a/toonz/sources/toonz/sceneviewer.cpp
+++ b/toonz/sources/toonz/sceneviewer.cpp
@@ -782,6 +782,8 @@ void SceneViewer::showEvent(QShowEvent *) {
     m_shownOnce = true;
   }
   TApp::instance()->setActiveViewer(this);
+
+  update();
 }
 
 //-----------------------------------------------------------------------------