diff --git a/src/msw/app.cpp b/src/msw/app.cpp
index e8718ccdd9..0e79d4627f 100644
--- a/src/msw/app.cpp
+++ b/src/msw/app.cpp
@@ -820,6 +820,10 @@ void wxApp::WakeUpIdle()
             }
         }
     }
+#if wxUSE_THREADS
+    else
+        wxWakeUpMainThread();
+#endif // wxUSE_THREADS
 }
 
 // ----------------------------------------------------------------------------