diff --git a/freezerclient/tests/unit/test_shell.py b/freezerclient/tests/unit/test_shell.py
index c1b825f..8829383 100644
--- a/freezerclient/tests/unit/test_shell.py
+++ b/freezerclient/tests/unit/test_shell.py
@@ -17,7 +17,7 @@ import re
 import sys
 
 import fixtures
-import six
+import io
 import testtools
 from testtools import matchers
 
@@ -58,8 +58,8 @@ class ShellTest(testtools.TestCase):
         clean_env = {}
         _old_env, os.environ = os.environ, clean_env.copy()
         try:
-            sys.stdout = six.moves.cStringIO()
-            sys.stderr = six.moves.cStringIO()
+            sys.stdout = io.StringIO()
+            sys.stderr = io.StringIO()
             _shell = openstack_shell.FreezerShell()
             _shell.run(argstr.split())
         except SystemExit:
diff --git a/lower-constraints.txt b/lower-constraints.txt
index b5424ad..c21d4c2 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -42,7 +42,6 @@ PyYAML==3.12
 reno==2.5.0
 requests==2.14.2
 setuptools==21.0.0
-six==1.10.0
 snowballstemmer==1.2.1
 Sphinx==1.6.5
 sphinxcontrib-websupport==1.0.1