diff --git a/lower-constraints.txt b/lower-constraints.txt
index 2b77dff..0c7cab1 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -28,7 +28,6 @@
 linecache2==1.0.0
 MarkupSafe==1.0
 mccabe==0.2.1
-mock==2.0.0
 monotonic==1.4
 mox3==0.25.0
 msgpack==0.5.6
diff --git a/patrole_tempest_plugin/tests/unit/fixtures.py b/patrole_tempest_plugin/tests/unit/fixtures.py
index 41afe9b..2ce1d08 100644
--- a/patrole_tempest_plugin/tests/unit/fixtures.py
+++ b/patrole_tempest_plugin/tests/unit/fixtures.py
@@ -15,9 +15,9 @@
 
 """Fixtures for Patrole tests."""
 from __future__ import absolute_import
+from unittest import mock
 
 import fixtures
-import mock
 import time
 
 from tempest.common import credentials_factory as credentials
diff --git a/patrole_tempest_plugin/tests/unit/test_policy_authority.py b/patrole_tempest_plugin/tests/unit/test_policy_authority.py
index 185e449..cdc9e15 100644
--- a/patrole_tempest_plugin/tests/unit/test_policy_authority.py
+++ b/patrole_tempest_plugin/tests/unit/test_policy_authority.py
@@ -13,8 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
 import os
+from unittest import mock
 
 from tempest import config
 
diff --git a/patrole_tempest_plugin/tests/unit/test_rbac_rule_validation.py b/patrole_tempest_plugin/tests/unit/test_rbac_rule_validation.py
index 5c4efff..2c7307e 100644
--- a/patrole_tempest_plugin/tests/unit/test_rbac_rule_validation.py
+++ b/patrole_tempest_plugin/tests/unit/test_rbac_rule_validation.py
@@ -13,9 +13,9 @@
 #    under the License.
 
 from __future__ import absolute_import
+from unittest import mock
 
 import functools
-import mock
 from oslo_config import cfg
 
 import fixtures
diff --git a/patrole_tempest_plugin/tests/unit/test_rbac_utils.py b/patrole_tempest_plugin/tests/unit/test_rbac_utils.py
index e84a56d..e61f798 100644
--- a/patrole_tempest_plugin/tests/unit/test_rbac_utils.py
+++ b/patrole_tempest_plugin/tests/unit/test_rbac_utils.py
@@ -13,8 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
 import testtools
+from unittest import mock
 
 from tempest.lib import exceptions as lib_exc
 
diff --git a/test-requirements.txt b/test-requirements.txt
index 63f290c..638bd37 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -3,7 +3,6 @@
 # process, which may cause wedges in the gate later.
 hacking>=3.0,<3.1.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD
-mock>=2.0.0 # BSD
 coverage!=4.4,>=4.0 # Apache-2.0
 nose>=1.3.7 # LGPL
 nosexcover>=1.0.10 # BSD