Index: cherrypy/__init__.py
===================================================================
--- cherrypy/__init__.py	(revision 1932)
+++ cherrypy/__init__.py	(working copy)
@@ -319,7 +319,7 @@
     
     def _get_dict(self):
         child = getattr(serving, self.__attrname__)
-        d = child.__class__.__dict__.copy()
+        d = dict(child.__class__.__dict__).copy()
         d.update(child.__dict__)
         return d
     __dict__ = property(_get_dict)