diff --git a/wxPython/src/_mdi.i b/wxPython/src/_mdi.i
index f5607a591c..ae3d1f9fbb 100644
--- a/wxPython/src/_mdi.i
+++ b/wxPython/src/_mdi.i
@@ -109,7 +109,7 @@ public:
                     const wxString& name = wxPyFrameNameStr);
 
     void Activate();
-    void Maximize(bool maximize);
+    void Maximize(bool maximize=true);
     void Restore();
 
 };