diff --git a/include/wx/mac/carbon/dialog.h b/include/wx/mac/carbon/dialog.h
index b73d05e911..c1e0c03e45 100644
--- a/include/wx/mac/carbon/dialog.h
+++ b/include/wx/mac/carbon/dialog.h
@@ -16,8 +16,6 @@
 
 WXDLLEXPORT_DATA(extern const wxChar*) wxDialogNameStr;
 
-WXDLLEXPORT_DATA(extern const wxChar*) wxDialogNameStr;
-
 class WXDLLEXPORT wxMacToolTip ;
 
 // Dialog boxes