diff --git a/include/wx/msw/bitmap.h b/include/wx/msw/bitmap.h
index e7919e482e..650d75c4d4 100644
--- a/include/wx/msw/bitmap.h
+++ b/include/wx/msw/bitmap.h
@@ -131,6 +131,7 @@ public:
   wxBitmap(const char bits[], const int width, const int height, const int depth = 1);
 
 #if USE_XPM_IN_MSW
+  class wxItem;
   // Initialize with XPM data
   wxBitmap(const char **data, wxItem *anItem = NULL);
 #endif