diff --git a/doc/requirements.txt b/doc/requirements.txt
index 271c18b2..cdd1af97 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -10,7 +10,6 @@ sphinxcontrib-apidoc>=0.2.0  # BSD
 
 # For autodoc builds
 fixtures>=3.0.0 # Apache-2.0/BSD
-mock>=2.0.0 # BSD
 betamax>=0.7.0 # Apache-2.0
 oslo.config>=5.2.0 # Apache-2.0
 oslo.utils>=3.33.0 # Apache-2.0
diff --git a/keystoneauth1/fixture/keystoneauth_betamax.py b/keystoneauth1/fixture/keystoneauth_betamax.py
index a1aea161..3a05d965 100644
--- a/keystoneauth1/fixture/keystoneauth_betamax.py
+++ b/keystoneauth1/fixture/keystoneauth_betamax.py
@@ -13,10 +13,10 @@
 """A fixture to wrap the session constructor for use with Betamax."""
 
 from functools import partial
+from unittest import mock
 
 import betamax
 import fixtures
-import mock
 import requests
 
 from keystoneauth1.fixture import hooks
diff --git a/keystoneauth1/tests/unit/loading/test_cli.py b/keystoneauth1/tests/unit/loading/test_cli.py
index 5bbc32c9..51635336 100644
--- a/keystoneauth1/tests/unit/loading/test_cli.py
+++ b/keystoneauth1/tests/unit/loading/test_cli.py
@@ -11,10 +11,10 @@
 # under the License.
 
 import argparse
+from unittest import mock
 import uuid
 
 import fixtures
-import mock
 
 from keystoneauth1 import loading
 from keystoneauth1.loading import cli
diff --git a/keystoneauth1/tests/unit/loading/test_conf.py b/keystoneauth1/tests/unit/loading/test_conf.py
index 2f99388a..ccea2b95 100644
--- a/keystoneauth1/tests/unit/loading/test_conf.py
+++ b/keystoneauth1/tests/unit/loading/test_conf.py
@@ -10,9 +10,9 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from unittest import mock
 import uuid
 
-import mock
 from oslo_config import cfg
 from oslo_config import fixture as config
 import stevedore
diff --git a/keystoneauth1/tests/unit/loading/utils.py b/keystoneauth1/tests/unit/loading/utils.py
index 0e3c2b94..3b4f6755 100644
--- a/keystoneauth1/tests/unit/loading/utils.py
+++ b/keystoneauth1/tests/unit/loading/utils.py
@@ -11,9 +11,9 @@
 # under the License.
 
 import functools
+from unittest import mock
 import uuid
 
-import mock
 
 from keystoneauth1 import loading
 from keystoneauth1.loading import base
diff --git a/keystoneauth1/tests/unit/test_betamax_fixture.py b/keystoneauth1/tests/unit/test_betamax_fixture.py
index 8984dcd9..fb181994 100644
--- a/keystoneauth1/tests/unit/test_betamax_fixture.py
+++ b/keystoneauth1/tests/unit/test_betamax_fixture.py
@@ -10,9 +10,10 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from unittest import mock
+
 import betamax
 from betamax import exceptions
-import mock
 import testtools
 
 from keystoneauth1.fixture import keystoneauth_betamax
diff --git a/keystoneauth1/tests/unit/test_betamax_hooks.py b/keystoneauth1/tests/unit/test_betamax_hooks.py
index 038eb43c..8c5116fe 100644
--- a/keystoneauth1/tests/unit/test_betamax_hooks.py
+++ b/keystoneauth1/tests/unit/test_betamax_hooks.py
@@ -11,9 +11,9 @@
 # under the License.
 
 import json
+from unittest import mock
 
 import betamax
-import mock
 from requests import models
 import testtools
 
diff --git a/keystoneauth1/tests/unit/test_discovery.py b/keystoneauth1/tests/unit/test_discovery.py
index faa866cd..9fe6cd94 100644
--- a/keystoneauth1/tests/unit/test_discovery.py
+++ b/keystoneauth1/tests/unit/test_discovery.py
@@ -12,8 +12,8 @@
 
 import json
 import re
+from unittest import mock
 
-import mock
 from testtools import matchers
 
 from keystoneauth1 import adapter
diff --git a/keystoneauth1/tests/unit/test_fair_sempahore.py b/keystoneauth1/tests/unit/test_fair_sempahore.py
index 709968ae..7e2f0287 100644
--- a/keystoneauth1/tests/unit/test_fair_sempahore.py
+++ b/keystoneauth1/tests/unit/test_fair_sempahore.py
@@ -12,8 +12,8 @@
 
 from threading import Thread
 from timeit import default_timer as timer
+from unittest import mock
 
-import mock
 from six.moves import queue
 import testtools
 
diff --git a/keystoneauth1/tests/unit/test_hacking_checks.py b/keystoneauth1/tests/unit/test_hacking_checks.py
index 958b6733..751ac29c 100644
--- a/keystoneauth1/tests/unit/test_hacking_checks.py
+++ b/keystoneauth1/tests/unit/test_hacking_checks.py
@@ -11,8 +11,8 @@
 # under the License.
 
 import textwrap
+from unittest import mock
 
-import mock
 import pycodestyle
 import testtools
 
diff --git a/keystoneauth1/tests/unit/test_session.py b/keystoneauth1/tests/unit/test_session.py
index 8817e4e7..fed14584 100644
--- a/keystoneauth1/tests/unit/test_session.py
+++ b/keystoneauth1/tests/unit/test_session.py
@@ -15,9 +15,9 @@ import itertools
 import json
 import logging
 import sys
+from unittest import mock
 import uuid
 
-import mock
 from oslo_utils import encodeutils
 import requests
 import requests.auth
@@ -978,7 +978,7 @@ class SessionAuthTests(utils.TestCase):
         mock_close = mock.Mock()
         sess._session.close = mock_close
         del sess
-        mock_close.assert_called_once()
+        self.assertEqual(1, mock_close.call_count)
 
     def test_service_type_urls(self):
         service_type = 'compute'
diff --git a/test-requirements.txt b/test-requirements.txt
index 07116f3f..c84281d1 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -10,7 +10,6 @@ pycodestyle>=2.0.0,<2.6.0 # MIT
 bandit<1.6.0,>=1.1.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD
-mock>=2.0.0 # BSD
 oslo.config>=5.2.0 # Apache-2.0
 oslo.utils>=3.33.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0