diff --git a/src/msw/taskbar.cpp b/src/msw/taskbar.cpp
index f40210841c..22583439bf 100644
--- a/src/msw/taskbar.cpp
+++ b/src/msw/taskbar.cpp
@@ -33,6 +33,11 @@
 #include "wx/platinfo.h"
 #include "wx/msw/private.h"
 
+#ifndef NIN_BALLOONTIMEOUT
+    #define NIN_BALLOONTIMEOUT      0x0404
+    #define NIN_BALLOONUSERCLICK    0x0405
+#endif
+
 // initialized on demand
 static UINT gs_msgTaskbar = 0;
 static UINT gs_msgRestartTaskbar = 0;