diff --git a/cleverhans/attacks.py b/cleverhans/attacks.py
index <HASH>..<HASH> 100644
--- a/cleverhans/attacks.py
+++ b/cleverhans/attacks.py
@@ -1,12 +1,12 @@
 from abc import ABCMeta
+import collections
+import warnings
+
 import numpy as np
 from six.moves import xrange
-import warnings
-import collections
 
 import cleverhans.utils as utils
 from cleverhans.model import Model, CallableModelWrapper
-from distutils.version import LooseVersion
 from cleverhans.compat import reduce_sum, reduce_mean
 from cleverhans.compat import reduce_max, reduce_min
 from cleverhans.compat import reduce_any
fix import order for attacks.py