diff --git a/src/msw/taskbar.cpp b/src/msw/taskbar.cpp
index 1e92de985d..45c1bef5e3 100644
--- a/src/msw/taskbar.cpp
+++ b/src/msw/taskbar.cpp
@@ -276,6 +276,7 @@ long wxTaskBarIcon::WindowProc(unsigned int msg,
     {
         m_iconAdded = false;
         SetIcon(m_icon, m_strTooltip);
+        return 0;
     }
 
     // this function should only be called for gs_msg(Restart)Taskbar messages