diff --git a/novaclient/tests/test_utils.py b/novaclient/tests/test_utils.py
index 64c97614f..8809133ac 100644
--- a/novaclient/tests/test_utils.py
+++ b/novaclient/tests/test_utils.py
@@ -1,7 +1,7 @@
-import io
 import sys
 
 import mock
+import six
 
 from novaclient import exceptions
 from novaclient import utils
@@ -112,7 +112,7 @@ class _FakeResult(object):
 
 
 class PrintResultTestCase(test_utils.TestCase):
-    @mock.patch('sys.stdout', io.BytesIO())
+    @mock.patch('sys.stdout', six.StringIO())
     def test_print_list_sort_by_str(self):
         objs = [_FakeResult("k1", 1),
                 _FakeResult("k3", 2),
@@ -129,7 +129,7 @@ class PrintResultTestCase(test_utils.TestCase):
                          '| k3   | 2     |\n'
                          '+------+-------+\n')
 
-    @mock.patch('sys.stdout', io.BytesIO())
+    @mock.patch('sys.stdout', six.StringIO())
     def test_print_list_sort_by_integer(self):
         objs = [_FakeResult("k1", 1),
                 _FakeResult("k3", 2),
@@ -147,7 +147,7 @@ class PrintResultTestCase(test_utils.TestCase):
                          '+------+-------+\n')
 
     # without sorting
-    @mock.patch('sys.stdout', io.BytesIO())
+    @mock.patch('sys.stdout', six.StringIO())
     def test_print_list_sort_by_none(self):
         objs = [_FakeResult("k1", 1),
                 _FakeResult("k3", 3),
diff --git a/novaclient/tests/v1_1/test_servers.py b/novaclient/tests/v1_1/test_servers.py
index 19cca5bb1..658068f77 100644
--- a/novaclient/tests/v1_1/test_servers.py
+++ b/novaclient/tests/v1_1/test_servers.py
@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
 
-import io
-
 import mock
 import six
 
@@ -56,7 +54,7 @@ class ServersTest(utils.TestCase):
             key_name="fakekey",
             files={
                 '/etc/passwd': 'some data',                 # a file
-                '/tmp/foo.txt': io.BytesIO('data'),   # a stream
+                '/tmp/foo.txt': six.StringIO('data'),   # a stream
             }
         )
         cs.assert_called('POST', '/servers')
@@ -100,10 +98,10 @@ class ServersTest(utils.TestCase):
             image=1,
             flavor=1,
             meta={'foo': 'bar'},
-            userdata=io.BytesIO('hello moto'),
+            userdata=six.StringIO('hello moto'),
             files={
                 '/etc/passwd': 'some data',                 # a file
-                '/tmp/foo.txt': io.BytesIO('data'),   # a stream
+                '/tmp/foo.txt': six.StringIO('data'),   # a stream
             },
         )
         cs.assert_called('POST', '/servers')
@@ -119,7 +117,7 @@ class ServersTest(utils.TestCase):
             key_name="fakekey",
             files={
                 '/etc/passwd': 'some data',                 # a file
-                '/tmp/foo.txt': io.BytesIO('data'),   # a stream
+                '/tmp/foo.txt': six.StringIO('data'),   # a stream
             },
         )
         cs.assert_called('POST', '/servers')
@@ -135,7 +133,7 @@ class ServersTest(utils.TestCase):
             key_name="fakekey",
             files={
                 '/etc/passwd': 'some data',                 # a file
-                '/tmp/foo.txt': io.BytesIO('data'),   # a stream
+                '/tmp/foo.txt': six.StringIO('data'),   # a stream
             },
         )
         cs.assert_called('POST', '/servers')
diff --git a/novaclient/tests/v1_1/test_shell.py b/novaclient/tests/v1_1/test_shell.py
index 236182c57..d7a5e0d38 100644
--- a/novaclient/tests/v1_1/test_shell.py
+++ b/novaclient/tests/v1_1/test_shell.py
@@ -17,13 +17,13 @@
 #    under the License.
 
 import datetime
-import io
 import os
 import mock
 import sys
 import tempfile
 
 import fixtures
+import six
 
 import novaclient.client
 from novaclient import exceptions
@@ -71,7 +71,7 @@ class ShellTest(utils.TestCase):
             lambda *_: fakes.FakeClient))
         self.addCleanup(timeutils.clear_time_override)
 
-    @mock.patch('sys.stdout', io.BytesIO())
+    @mock.patch('sys.stdout', six.StringIO())
     def run_command(self, cmd):
         if isinstance(cmd, list):
             self.shell.main(cmd)