diff --git a/include/wx/generic/grid.h b/include/wx/generic/grid.h
index 8825ffe555..7468fca53a 100644
--- a/include/wx/generic/grid.h
+++ b/include/wx/generic/grid.h
@@ -1118,7 +1118,8 @@ public:
 
     int      GetBatchCount() { return m_batchCount; }
 
-    virtual void Refresh(bool eraseb=true, wxRect* rect= NULL); 
+    virtual void Refresh(bool eraseb = true,
+                         const wxRect* rect = (const wxRect *)  NULL); 
 
     // Use this, rather than wxWindow::Refresh(), to force an
     // immediate repainting of the grid. Has no effect if you are