diff --git a/include/wx/toplevel.h b/include/wx/toplevel.h
index 47c5798ebc..50b5e26121 100644
--- a/include/wx/toplevel.h
+++ b/include/wx/toplevel.h
@@ -24,8 +24,6 @@
 // the default names for various classes
 extern WXDLLIMPEXP_DATA_CORE(const char) wxFrameNameStr[];
 
-class WXDLLIMPEXP_FWD_CORE wxTopLevelWindowBase;
-
 // ----------------------------------------------------------------------------
 // constants
 // ----------------------------------------------------------------------------