diff --git a/include/wx/private/overlay.h b/include/wx/private/overlay.h
index c38ed99036..a811441fbf 100644
--- a/include/wx/private/overlay.h
+++ b/include/wx/private/overlay.h
@@ -27,7 +27,8 @@
 #else // !wxHAS_NATIVE_OVERLAY
 
 #include "wx/bitmap.h"
-#include "wx/window.h"
+
+class WXDLLIMPEXP_CORE wxWindow;
 
 // generic implementation of wxOverlay
 class wxOverlayImpl