diff --git a/masakarimonitors/tests/unit/ha/test_masakari.py b/masakarimonitors/tests/unit/ha/test_masakari.py
index f57ec9f..7297e7a 100644
--- a/masakarimonitors/tests/unit/ha/test_masakari.py
+++ b/masakarimonitors/tests/unit/ha/test_masakari.py
@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import testtools
+from unittest import mock
 import uuid
 
 import eventlet
diff --git a/masakarimonitors/tests/unit/hostmonitor/host_handler/test_handle_host.py b/masakarimonitors/tests/unit/hostmonitor/host_handler/test_handle_host.py
index 704167f..b12a335 100644
--- a/masakarimonitors/tests/unit/hostmonitor/host_handler/test_handle_host.py
+++ b/masakarimonitors/tests/unit/hostmonitor/host_handler/test_handle_host.py
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import socket
 import testtools
+from unittest import mock
 from xml.etree import ElementTree
 
 import eventlet
diff --git a/masakarimonitors/tests/unit/hostmonitor/host_handler/test_parse_cib_xml.py b/masakarimonitors/tests/unit/hostmonitor/host_handler/test_parse_cib_xml.py
index 1032236..d2fd598 100644
--- a/masakarimonitors/tests/unit/hostmonitor/host_handler/test_parse_cib_xml.py
+++ b/masakarimonitors/tests/unit/hostmonitor/host_handler/test_parse_cib_xml.py
@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import testtools
+from unittest import mock
 from xml.etree import ElementTree
 
 import eventlet
diff --git a/masakarimonitors/tests/unit/hostmonitor/test_host.py b/masakarimonitors/tests/unit/hostmonitor/test_host.py
index 296fe39..7c5c0d5 100644
--- a/masakarimonitors/tests/unit/hostmonitor/test_host.py
+++ b/masakarimonitors/tests/unit/hostmonitor/test_host.py
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import os
 import testtools
+from unittest import mock
 
 from stevedore import driver
 
diff --git a/masakarimonitors/tests/unit/instancemonitor/libvirt_handler/test_callback.py b/masakarimonitors/tests/unit/instancemonitor/libvirt_handler/test_callback.py
index 0190ab5..c6a7b77 100644
--- a/masakarimonitors/tests/unit/instancemonitor/libvirt_handler/test_callback.py
+++ b/masakarimonitors/tests/unit/instancemonitor/libvirt_handler/test_callback.py
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import socket
 import testtools
+from unittest import mock
 import uuid
 
 import eventlet
diff --git a/masakarimonitors/tests/unit/instancemonitor/libvirt_handler/test_eventfilter.py b/masakarimonitors/tests/unit/instancemonitor/libvirt_handler/test_eventfilter.py
index 094b905..6fcdd04 100644
--- a/masakarimonitors/tests/unit/instancemonitor/libvirt_handler/test_eventfilter.py
+++ b/masakarimonitors/tests/unit/instancemonitor/libvirt_handler/test_eventfilter.py
@@ -12,10 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import socket
 import testtools
 import threading
+from unittest import mock
 import uuid
 
 import eventlet
diff --git a/masakarimonitors/tests/unit/instancemonitor/test_instance.py b/masakarimonitors/tests/unit/instancemonitor/test_instance.py
index ead7d7e..4749c40 100644
--- a/masakarimonitors/tests/unit/instancemonitor/test_instance.py
+++ b/masakarimonitors/tests/unit/instancemonitor/test_instance.py
@@ -13,10 +13,10 @@
 # limitations under the License.
 
 import libvirt
-import mock
 import testtools
 import threading
 import time
+from unittest import mock
 import uuid
 
 import eventlet
diff --git a/masakarimonitors/tests/unit/introspectiveinstancemonitor/test_monitor_manager.py b/masakarimonitors/tests/unit/introspectiveinstancemonitor/test_monitor_manager.py
index efab397..5329b49 100644
--- a/masakarimonitors/tests/unit/introspectiveinstancemonitor/test_monitor_manager.py
+++ b/masakarimonitors/tests/unit/introspectiveinstancemonitor/test_monitor_manager.py
@@ -14,8 +14,8 @@
 
 import eventlet
 import libvirt
-import mock
 import testtools
+from unittest import mock
 
 from masakarimonitors.introspectiveinstancemonitor import instance
 
diff --git a/masakarimonitors/tests/unit/introspectiveinstancemonitor/test_qemu_utils.py b/masakarimonitors/tests/unit/introspectiveinstancemonitor/test_qemu_utils.py
index b4ec728..e178909 100755
--- a/masakarimonitors/tests/unit/introspectiveinstancemonitor/test_qemu_utils.py
+++ b/masakarimonitors/tests/unit/introspectiveinstancemonitor/test_qemu_utils.py
@@ -13,8 +13,8 @@
 # limitations under the License.
 
 import libvirt
-import mock
 import testtools
+from unittest import mock
 import uuid
 
 
diff --git a/masakarimonitors/tests/unit/processmonitor/process_handler/test_handle_process.py b/masakarimonitors/tests/unit/processmonitor/process_handler/test_handle_process.py
index 912bd05..fa20d8c 100644
--- a/masakarimonitors/tests/unit/processmonitor/process_handler/test_handle_process.py
+++ b/masakarimonitors/tests/unit/processmonitor/process_handler/test_handle_process.py
@@ -12,9 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import socket
 import testtools
+from unittest import mock
 
 import eventlet
 from oslo_utils import timeutils
diff --git a/masakarimonitors/tests/unit/processmonitor/test_process.py b/masakarimonitors/tests/unit/processmonitor/test_process.py
index 51be4f5..73cfd1c 100644
--- a/masakarimonitors/tests/unit/processmonitor/test_process.py
+++ b/masakarimonitors/tests/unit/processmonitor/test_process.py
@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import testtools
+from unittest import mock
 import yaml
 
 import eventlet
diff --git a/masakarimonitors/tests/unit/test_hacking.py b/masakarimonitors/tests/unit/test_hacking.py
index 8412fcc..129bec9 100644
--- a/masakarimonitors/tests/unit/test_hacking.py
+++ b/masakarimonitors/tests/unit/test_hacking.py
@@ -13,8 +13,8 @@
 #    under the License.
 
 import textwrap
+from unittest import mock
 
-import mock
 import pycodestyle
 import testtools