diff --git a/vncviewer/ViewerToolBar.h b/vncviewer/ViewerToolBar.h
index 8e829e7..30e7708 100644
--- a/vncviewer/ViewerToolBar.h
+++ b/vncviewer/ViewerToolBar.h
@@ -31,6 +31,8 @@
 
   void create(HWND parentHwnd);
 
+  LRESULT processWM_NOTIFY(WPARAM wParam, LPARAM lParam);
+
   void show();
   void hide();
 };