diff --git a/zipline/utils/protocol_utils.py b/zipline/utils/protocol_utils.py
index c74c81f2..c3ae9352 100644
--- a/zipline/utils/protocol_utils.py
+++ b/zipline/utils/protocol_utils.py
@@ -2,7 +2,6 @@ import copy
 import pandas
 from ctypes import Structure, c_ubyte
 from collections import MutableMapping
-from itertools import izip
 
 def Enum(*options):
     """