diff --git a/lower-constraints.txt b/lower-constraints.txt
index 29580e8..102b938 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -31,7 +31,6 @@ reno==3.1.0
 requests==2.14.2
 requestsexceptions==1.2.0
 rfc3986==0.3.1
-six==1.10.0
 smmap==0.9.0
 snowballstemmer==1.2.1
 Sphinx==2.0.0
diff --git a/oslo_i18n/_gettextutils.py b/oslo_i18n/_gettextutils.py
index 9872a9c..19f093b 100644
--- a/oslo_i18n/_gettextutils.py
+++ b/oslo_i18n/_gettextutils.py
@@ -44,9 +44,9 @@ def install(domain):
 
     :param domain: the translation domain
     """
-    from six import moves
+    import builtins
     tf = _factory.TranslatorFactory(domain)
-    moves.builtins.__dict__['_'] = tf.primary
+    builtins.__dict__['_'] = tf.primary
 
 
 _AVAILABLE_LANGUAGES = {}
diff --git a/oslo_i18n/_message.py b/oslo_i18n/_message.py
index 1d94e8d..a73992e 100644
--- a/oslo_i18n/_message.py
+++ b/oslo_i18n/_message.py
@@ -23,8 +23,6 @@ import logging
 import os
 import warnings
 
-import six
-
 from oslo_i18n import _locale
 from oslo_i18n import _translate
 
@@ -35,7 +33,7 @@ CONTEXT_SEPARATOR = "\x04"
 LOG = logging.getLogger(__name__)
 
 
-class Message(six.text_type):
+class Message(str):
     """A Message object is a unicode object that can be translated.
 
     Translation of Message is done explicitly using the translate() method.
@@ -184,7 +182,7 @@ class Message(six.text_type):
         # by the base class (i.e. unicode()), the only thing  we do here is
         # save the original msgid and the parameters in case of a translation
         params = self._sanitize_mod_params(other)
-        unicode_mod = self._safe_translate(six.text_type(self), params)
+        unicode_mod = self._safe_translate(str(self), params)
         modded = Message(self.msgid,
                          msgtext=unicode_mod,
                          params=params,
@@ -221,7 +219,7 @@ class Message(six.text_type):
         except Exception:
             # Fallback to casting to unicode this will handle the
             # python code-like objects that can't be deep-copied
-            return six.text_type(param)
+            return str(param)
 
     def __add__(self, other):
         from oslo_i18n._i18n import _
diff --git a/oslo_i18n/_translate.py b/oslo_i18n/_translate.py
index 9d68beb..2a35741 100644
--- a/oslo_i18n/_translate.py
+++ b/oslo_i18n/_translate.py
@@ -14,8 +14,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import six
-
 __all__ = [
     'translate',
 ]
@@ -41,7 +39,7 @@ def translate(obj, desired_locale=None):
     if not isinstance(message, _message.Message):
         # If the object to translate is not already translatable,
         # let's first get its unicode representation
-        message = six.text_type(obj)
+        message = str(obj)
     if isinstance(message, _message.Message):
         # Even after unicoding() we still need to check if we are
         # running with translatable unicode before translating
diff --git a/oslo_i18n/fixture.py b/oslo_i18n/fixture.py
index 35dc694..5c5fddc 100644
--- a/oslo_i18n/fixture.py
+++ b/oslo_i18n/fixture.py
@@ -16,7 +16,6 @@
 import gettext
 
 import fixtures
-import six
 
 from oslo_i18n import _lazy
 from oslo_i18n import _message
@@ -65,7 +64,7 @@ class Translation(fixtures.Fixture):
         :type msg: str or unicode
 
         """
-        return six.text_type(msg)
+        return str(msg)
 
 
 class ToggleLazy(fixtures.Fixture):
diff --git a/oslo_i18n/tests/test_factory.py b/oslo_i18n/tests/test_factory.py
index 34effb5..fbc585b 100644
--- a/oslo_i18n/tests/test_factory.py
+++ b/oslo_i18n/tests/test_factory.py
@@ -17,7 +17,6 @@
 from unittest import mock
 
 from oslotest import base as test_base
-import six
 
 from oslo_i18n import _factory
 from oslo_i18n import _lazy
@@ -62,48 +61,9 @@ class TranslatorFactoryTest(test_base.BaseTestCase):
         r = tf.primary('some text')
         self.assertNotIsInstance(r, _message.Message)
 
-    def test_py3(self):
-        _lazy.enable_lazy(False)
-        with mock.patch.object(six, 'PY3', True):
-            with mock.patch('gettext.translation') as translation:
-                trans = mock.Mock()
-                translation.return_value = trans
-                trans.ugettext.side_effect = AssertionError(
-                    'should have called gettext')
-                tf = _factory.TranslatorFactory('domain')
-                tf.primary('some text')
-                trans.gettext.assert_called_with('some text')
-
     def test_log_level_domain_name(self):
         with mock.patch.object(_factory.TranslatorFactory,
                                '_make_translation_func') as mtf:
             tf = _factory.TranslatorFactory('domain')
             tf._make_log_translation_func('mylevel')
             mtf.assert_called_with('domain-log-mylevel')
-
-    def test_contextual_form_py3(self):
-        _lazy.enable_lazy(False)
-        with mock.patch.object(six, 'PY3', True):
-            with mock.patch('gettext.translation') as translation:
-                trans = mock.Mock()
-                translation.return_value = trans
-                trans.ugettext.side_effect = AssertionError(
-                    'should have called gettext')
-                trans.gettext.return_value = "some text"
-                tf = _factory.TranslatorFactory('domain')
-                tf.contextual_form('context', 'some text')
-                trans.gettext.assert_called_with(
-                    "%s%s%s" % ('context', CONTEXT_SEPARATOR, 'some text'))
-
-    def test_plural_form_py3(self):
-        _lazy.enable_lazy(False)
-        with mock.patch.object(six, 'PY3', True):
-            with mock.patch('gettext.translation') as translation:
-                trans = mock.Mock()
-                translation.return_value = trans
-                trans.ungettext.side_effect = AssertionError(
-                    'should have called ngettext')
-                tf = _factory.TranslatorFactory('domain')
-                tf.plural_form('single', 'plural', 1)
-                trans.ngettext.assert_called_with(
-                    'single', 'plural', 1)
diff --git a/oslo_i18n/tests/test_fixture.py b/oslo_i18n/tests/test_fixture.py
index a152ce3..5b4eaa5 100644
--- a/oslo_i18n/tests/test_fixture.py
+++ b/oslo_i18n/tests/test_fixture.py
@@ -13,7 +13,6 @@
 #    under the License.
 
 from oslotest import base as test_base
-import six
 
 import oslo_i18n
 from oslo_i18n import _gettextutils
@@ -38,7 +37,7 @@ class TranslationFixtureTest(test_base.BaseTestCase):
     def test_immediate(self):
         msg = self.trans_fixture.immediate('this is a lazy message')
         self.assertNotIsInstance(msg, _message.Message)
-        self.assertIsInstance(msg, six.text_type)
+        self.assertIsInstance(msg, str)
         self.assertEqual(u'this is a lazy message', msg)
 
 
diff --git a/oslo_i18n/tests/test_gettextutils.py b/oslo_i18n/tests/test_gettextutils.py
index 4e0999b..580aba9 100644
--- a/oslo_i18n/tests/test_gettextutils.py
+++ b/oslo_i18n/tests/test_gettextutils.py
@@ -14,12 +14,12 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import builtins
 import gettext
 import logging
 from unittest import mock
 
 from oslotest import base as test_base
-import six
 
 from oslo_i18n import _factory
 from oslo_i18n import _gettextutils
@@ -49,8 +49,7 @@ class GettextTest(test_base.BaseTestCase):
     def test__gettextutils_install(self):
         _gettextutils.install('blaa')
         _lazy.enable_lazy(False)
-        self.assertTrue(isinstance(self.t.primary('A String'),
-                                   six.text_type))
+        self.assertTrue(isinstance(self.t.primary('A String'), str))
 
         _gettextutils.install('blaa')
         _lazy.enable_lazy(True)
@@ -68,10 +67,10 @@ class GettextTest(test_base.BaseTestCase):
         with mock.patch('os.environ.get') as environ_get:
             with mock.patch('gettext.install'):
                 environ_get.return_value = '/foo/bar'
-                if '_' in six.moves.builtins.__dict__:
-                    del six.moves.builtins.__dict__['_']
+                if '_' in builtins.__dict__:
+                    del builtins.__dict__['_']
                 _gettextutils.install('blaa')
-                self.assertIn('_', six.moves.builtins.__dict__)
+                self.assertIn('_', builtins.__dict__)
 
     def test_get_available_languages(self):
         # Only the languages available for a specific translation domain
diff --git a/oslo_i18n/tests/test_handler.py b/oslo_i18n/tests/test_handler.py
index ffa9f8e..86dbe8d 100644
--- a/oslo_i18n/tests/test_handler.py
+++ b/oslo_i18n/tests/test_handler.py
@@ -14,11 +14,11 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import io
 import logging
 from unittest import mock
 
 from oslotest import base as test_base
-import six
 
 from oslo_i18n import _message
 from oslo_i18n import log as i18n_log
@@ -32,7 +32,7 @@ class TranslationHandlerTestCase(test_base.BaseTestCase):
     def setUp(self):
         super(TranslationHandlerTestCase, self).setUp()
 
-        self.stream = six.StringIO()
+        self.stream = io.StringIO()
         self.destination_handler = logging.StreamHandler(self.stream)
         self.translation_handler = i18n_log.TranslationHandler('zh_CN')
         self.translation_handler.setTarget(self.destination_handler)
diff --git a/oslo_i18n/tests/test_message.py b/oslo_i18n/tests/test_message.py
index f6d7fc6..85dbd67 100644
--- a/oslo_i18n/tests/test_message.py
+++ b/oslo_i18n/tests/test_message.py
@@ -19,7 +19,6 @@ from unittest import mock
 import warnings
 
 from oslotest import base as test_base
-import six
 import testtools
 
 from oslo_i18n import _message
@@ -42,7 +41,7 @@ class MessageTestCase(test_base.BaseTestCase):
 
     def test_message_is_unicode(self):
         message = _message.Message('some %s') % 'message'
-        self.assertIsInstance(message, six.text_type)
+        self.assertIsInstance(message, str)
 
     @mock.patch('locale.getdefaultlocale')
     @mock.patch('gettext.translation')
@@ -67,7 +66,7 @@ class MessageTestCase(test_base.BaseTestCase):
 
     def test_translation_returns_unicode(self):
         message = _message.Message('some %s') % 'message'
-        self.assertIsInstance(message.translation(), six.text_type)
+        self.assertIsInstance(message.translation(), str)
 
     def test_mod_with_named_parameters(self):
         msgid = ("%(description)s\nCommand: %(cmd)s\n"
@@ -324,7 +323,7 @@ class MessageTestCase(test_base.BaseTestCase):
         # Here we are not testing the Message object directly but the result
         # of unicoding() an object whose unicode representation is a Message
         obj = utils.SomeObject(message)
-        unicoded_obj = six.text_type(obj)
+        unicoded_obj = str(obj)
 
         self.assertEqual(es_translation, unicoded_obj.translation('es'))
 
@@ -491,7 +490,7 @@ class MessageTestCase(test_base.BaseTestCase):
         expected_translation = es_translation % param
 
         obj = utils.SomeObject(msg)
-        unicoded_obj = six.text_type(obj)
+        unicoded_obj = str(obj)
 
         self.assertEqual(expected_translation, unicoded_obj.translation('es'))
         self.assertEqual(default_translation, unicoded_obj.translation('XX'))
diff --git a/oslo_i18n/tests/test_public_api.py b/oslo_i18n/tests/test_public_api.py
index c08384a..bf7a89a 100644
--- a/oslo_i18n/tests/test_public_api.py
+++ b/oslo_i18n/tests/test_public_api.py
@@ -12,7 +12,6 @@
 """A few tests that use the public API to ensure the imports work."""
 
 import unittest
-from unittest import mock
 
 import oslo_i18n
 from oslo_i18n import _lazy
@@ -24,8 +23,7 @@ class PublicAPITest(unittest.TestCase):
         oslo_i18n.TranslatorFactory('domain')
 
     def test_install(self):
-        with mock.patch('six.moves.builtins'):
-            oslo_i18n.install('domain')
+        oslo_i18n.install('domain')
 
     def test_get_available_languages(self):
         oslo_i18n.get_available_languages('domains')
diff --git a/requirements.txt b/requirements.txt
index a072ac0..6de9f4e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,4 +3,3 @@
 # process, which may cause wedges in the gate later.
 
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
-six>=1.10.0 # MIT