diff --git a/wxPython/src/controls2.i b/wxPython/src/controls2.i
index 9ace2b41ff..82116bb914 100644
--- a/wxPython/src/controls2.i
+++ b/wxPython/src/controls2.i
@@ -1003,7 +1003,11 @@ public:
     wxTreeItemId();
     ~wxTreeItemId();
     bool IsOk();
-    %pragma(python) addtoclass = "Ok = IsOk"
+    %pragma(python) addtoclass = "
+    Ok = IsOk
+    def __nonzero__(self):
+        return self.IsOk()
+"
 
     %addmethods {
         int __cmp__(wxTreeItemId* other) {