diff --git a/src/msw/dirdlg.cpp b/src/msw/dirdlg.cpp
index e736175a5c..9936da7cfc 100644
--- a/src/msw/dirdlg.cpp
+++ b/src/msw/dirdlg.cpp
@@ -37,6 +37,7 @@
     #include "wx/dialog.h"
     #include "wx/dirdlg.h"
     #include "wx/log.h"
+    #include "wx/app/h"
 #endif
 
 #include "wx/msw/private.h"