diff --git a/zipline/assets/assets.py b/zipline/assets/assets.py
index 64c684d9..827d3447 100644
--- a/zipline/assets/assets.py
+++ b/zipline/assets/assets.py
@@ -13,9 +13,9 @@
 # limitations under the License.
 
 from abc import ABCMeta
-from functools import partial, itemgetter
+from functools import partial
 from numbers import Integral
-from operator import getitem
+from operator import getitem, itemgetter
 import warnings
 
 from logbook import Logger