diff --git a/interface/wx/artprov.h b/interface/wx/artprov.h
index cc25af31ec..149e49ba42 100644
--- a/interface/wx/artprov.h
+++ b/interface/wx/artprov.h
@@ -9,12 +9,12 @@
 /**
     This type identifies the client of the art objects requested to wxArtProvider.
 */
-typedef wxString wxArtClient;
+typedef class wxString wxArtClient;
 
 /**
     This type identifies a specific art object which can be requested to wxArtProvider.
 */
-typedef wxString wxArtID;
+typedef class wxString wxArtID;
 
 
 /**