Index: google/appengine/ext/db/__init__.py
===================================================================
--- google/appengine/ext/db/__init__.py	(revision 11)
+++ google/appengine/ext/db/__init__.py	(working copy)
@@ -1201,7 +1201,7 @@
     Args:
       entity: Entity which contain values to search dyanmic properties for.
     """
-    entity_values = Model._load_entity_values(entity)
+    entity_values = super(Expando, cls)._load_entity_values(entity)
     for key, value in entity.iteritems():
       if key not in entity_values:
         entity_values[str(key)] = value