diff --git a/acme/acme/crypto_util.py b/acme/acme/crypto_util.py
index 8893dd53f..58e2aecf3 100644
--- a/acme/acme/crypto_util.py
+++ b/acme/acme/crypto_util.py
@@ -4,7 +4,7 @@ import logging
 import socket
 import sys
 
-from six.moves import range  # pylint: disable=import-error
+from six.moves import range  # pylint: disable=import-error,redefined-builtin
 
 import OpenSSL
 
diff --git a/letsencrypt/tests/achallenges_test.py b/letsencrypt/tests/achallenges_test.py
index 0ad47cbc9..3d46c781a 100644
--- a/letsencrypt/tests/achallenges_test.py
+++ b/letsencrypt/tests/achallenges_test.py
@@ -7,8 +7,6 @@ from acme import challenges
 from acme import crypto_util as acme_crypto_util
 from acme import jose
 
-from letsencrypt import crypto_util
-
 from letsencrypt.tests import acme_util
 from letsencrypt.tests import test_util