diff --git a/.zuul.yaml b/.zuul.yaml
index 34184f1..fd189e2 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -1,4 +1,3 @@
 - project:
     templates:
-      - python35-charm-jobs
       - openstack-python3-ussuri-jobs
diff --git a/test-requirements.txt b/test-requirements.txt
index f853625..0aabe17 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -13,11 +13,6 @@ setuptools<50.0.0  # https://github.com/pypa/setuptools/commit/04e3df22df840c6bb
 
 requests>=2.18.4
 
-# Newer mock seems to have some syntax which is newer than python3.5 (e.g.
-# f'{something}'
-mock>=1.2,<4.0.0; python_version < '3.6'
-mock>=1.2; python_version >= '3.6'
-
 stestr>=2.2.0
 
 # Dependency of stestr. Workaround for
diff --git a/unit_tests/test_actions.py b/unit_tests/test_actions.py
index 6f37c83..d921671 100644
--- a/unit_tests/test_actions.py
+++ b/unit_tests/test_actions.py
@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
-from mock import patch
+from unittest import mock
+from unittest.mock import patch
 
 from test_utils import CharmTestCase
 
diff --git a/unit_tests/test_actions_openstack_upgrade.py b/unit_tests/test_actions_openstack_upgrade.py
index e884cde..b151d0f 100644
--- a/unit_tests/test_actions_openstack_upgrade.py
+++ b/unit_tests/test_actions_openstack_upgrade.py
@@ -15,7 +15,7 @@
 import os
 import sys
 
-from mock import patch, MagicMock
+from unittest.mock import patch, MagicMock
 
 # python-apt is not installed as part of test-requirements but is imported by
 # some charmhelpers modules so create a fake import.
diff --git a/unit_tests/test_ceilometer_contexts.py b/unit_tests/test_ceilometer_contexts.py
index 882bbc4..f74df98 100644
--- a/unit_tests/test_ceilometer_contexts.py
+++ b/unit_tests/test_ceilometer_contexts.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 import collections
-from mock import patch, MagicMock
+from unittest.mock import patch, MagicMock
 
 import ceilometer_contexts as contexts
 import ceilometer_utils as utils
diff --git a/unit_tests/test_ceilometer_hooks.py b/unit_tests/test_ceilometer_hooks.py
index a45d3d4..504e204 100644
--- a/unit_tests/test_ceilometer_hooks.py
+++ b/unit_tests/test_ceilometer_hooks.py
@@ -16,7 +16,7 @@ import copy
 import os
 import sys
 
-from mock import patch, MagicMock, call, mock_open
+from unittest.mock import patch, MagicMock, call, mock_open
 
 # python-apt is not installed as part of test-requirements but is imported by
 # some charmhelpers modules so create a fake import.
diff --git a/unit_tests/test_ceilometer_utils.py b/unit_tests/test_ceilometer_utils.py
index 2a6dedd..07b78e9 100644
--- a/unit_tests/test_ceilometer_utils.py
+++ b/unit_tests/test_ceilometer_utils.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from mock import patch, call, MagicMock
+from unittest.mock import patch, call, MagicMock
 
 import ceilometer_utils as utils
 
diff --git a/unit_tests/test_utils.py b/unit_tests/test_utils.py
index 8ee463f..8ab0afe 100644
--- a/unit_tests/test_utils.py
+++ b/unit_tests/test_utils.py
@@ -19,7 +19,7 @@ import yaml
 import io
 
 from contextlib import contextmanager
-from mock import patch
+from unittest.mock import patch
 
 
 @contextmanager