diff --git a/include/wx/artprov.h b/include/wx/artprov.h
index a8f59cb774..1b1fb6d15d 100644
--- a/include/wx/artprov.h
+++ b/include/wx/artprov.h
@@ -31,7 +31,7 @@ class wxArtProviderModule;
 typedef wxString wxArtClient;
 typedef wxString wxArtID;
 
-#define wxART_MAKE_CLIENT_ID_FROM_STR(id)  (wxString(id)+_T("_C"))
+#define wxART_MAKE_CLIENT_ID_FROM_STR(id)  (id + _T("_C"))
 #define wxART_MAKE_CLIENT_ID(id)           _T(#id) _T("_C")
 #define wxART_MAKE_ART_ID_FROM_STR(id)     (id)
 #define wxART_MAKE_ART_ID(id)              _T(#id)