diff --git a/src/msw/msgdlg.cpp b/src/msw/msgdlg.cpp
index 13e93e18c1..9468d76841 100644
--- a/src/msw/msgdlg.cpp
+++ b/src/msw/msgdlg.cpp
@@ -21,6 +21,7 @@
 #endif
 
 #ifndef WX_PRECOMP
+    #include "wx/app.h"
     #include "wx/defs.h"
     #include "wx/utils.h"
     #include "wx/dialog.h"