diff --git a/zipline/utils/protocol_utils.py b/zipline/utils/protocol_utils.py
index c027a70c..4c6f04d7 100644
--- a/zipline/utils/protocol_utils.py
+++ b/zipline/utils/protocol_utils.py
@@ -96,6 +96,14 @@ class ndict(MutableMapping):
     def __len__(self):
         return len(self.__internal)
 
+    #TODO: Eddie please help!
+    def __contains__(self, key):
+        if hasattr(self, '_ndict_contains__'):
+            return self._ndict_contains__(key)
+        else:
+             return self.__internal.__contains__(key)
+
+
     # Compatability with namedicts
     # ----------------------------