diff --git a/constance/admin.py b/constance/admin.py
index a011b70..64feedc 100644
--- a/constance/admin.py
+++ b/constance/admin.py
@@ -15,11 +15,12 @@ from django.core.files.storage import default_storage
 from django.forms import fields
 from django.http import HttpResponseRedirect
 from django.template.response import TemplateResponse
-from django.utils import six, timezone
+from django.utils import timezone
 from django.utils.encoding import smart_bytes
 from django.utils.formats import localize
 from django.utils.module_loading import import_string
 from django.utils.translation import ugettext_lazy as _
+import six
 
 from . import LazyConfig, settings
 from .checks import get_inconsistent_fieldnames
diff --git a/constance/backends/redisd.py b/constance/backends/redisd.py
index c7d522e..9e5bb58 100644
--- a/constance/backends/redisd.py
+++ b/constance/backends/redisd.py
@@ -1,6 +1,5 @@
 from django.core.exceptions import ImproperlyConfigured
-from django.utils import six
-from django.utils.six.moves import zip
+import six
 
 from . import Backend
 from .. import settings, utils, signals, config
@@ -43,7 +42,7 @@ class RedisBackend(Backend):
         if not keys:
             return
         prefixed_keys = [self.add_prefix(key) for key in keys]
-        for key, value in zip(keys, self._rd.mget(prefixed_keys)):
+        for key, value in six.moves.zip(keys, self._rd.mget(prefixed_keys)):
             if value:
                 yield key, loads(value)
 
diff --git a/setup.py b/setup.py
index 25950c7..6edb3d3 100644
--- a/setup.py
+++ b/setup.py
@@ -54,6 +54,7 @@ setup(
     packages=find_packages(exclude=['tests', 'tests.*']),
     include_package_data=True,
     zip_safe=False,
+    install_requires=['six'],
     extras_require={
         'database': ['django-picklefield'],
         'redis': ['redis'],
diff --git a/tests/test_cli.py b/tests/test_cli.py
index b0b9988..f8220b6 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -8,7 +8,7 @@ from django.core.management import call_command, CommandError
 from django.test import TransactionTestCase
 from django.utils import timezone
 from django.utils.encoding import smart_str
-from django.utils.six import StringIO
+from six import StringIO
 
 from constance import config