diff --git a/test-requirements.txt b/test-requirements.txt
index b755b49..4c0a30d 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -7,7 +7,6 @@ bandit!=1.6.0,>=1.1.0 # Apache-2.0
 Babel!=2.4.0,>=2.3.4 # BSD
 hacking>=1.1.0,<1.2.0 # Apache-2.0
 coverage!=4.4,>=4.0 # Apache-2.0
-mock>=2.0.0 # BSD
 stestr>=1.0.0 # Apache-2.0
 oslotest>=3.2.0 # Apache-2.0
 testrepository>=0.0.18 # Apache-2.0/BSD
diff --git a/tests/base.py b/tests/base.py
index f39572a..944ee59 100644
--- a/tests/base.py
+++ b/tests/base.py
@@ -12,8 +12,9 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from unittest import mock
+
 import fixtures
-import mock
 
 from oslo_config import cfg
 from oslo_config import fixture as oo_cfg
diff --git a/tests/test_alarm_processor.py b/tests/test_alarm_processor.py
index f341495..5fd6ce5 100644
--- a/tests/test_alarm_processor.py
+++ b/tests/test_alarm_processor.py
@@ -18,8 +18,8 @@
 
 import collections
 import json
-import mock
 import time
+from unittest import mock
 
 from monasca_common.kafka import legacy_kafka_message
 
diff --git a/tests/test_config.py b/tests/test_config.py
index 1d072b2..c9095bf 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -12,7 +12,8 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import mock
+from unittest import mock
+
 from oslo_config import cfg
 from oslo_utils import importutils
 import yaml
diff --git a/tests/test_email_notification.py b/tests/test_email_notification.py
index 5935829..5c0a4f7 100644
--- a/tests/test_email_notification.py
+++ b/tests/test_email_notification.py
@@ -21,8 +21,8 @@ import email.header
 import smtplib
 import socket
 import time
+from unittest import mock
 
-import mock
 import six
 
 from monasca_notification.notification import Notification
diff --git a/tests/test_hipchat_notification.py b/tests/test_hipchat_notification.py
index b5ef254..19575ee 100644
--- a/tests/test_hipchat_notification.py
+++ b/tests/test_hipchat_notification.py
@@ -12,7 +12,7 @@
 # limitations under the License.
 
 import json
-import mock
+from unittest import mock
 
 import six
 
diff --git a/tests/test_jira_notification.py b/tests/test_jira_notification.py
index 58d7587..3e59a00 100644
--- a/tests/test_jira_notification.py
+++ b/tests/test_jira_notification.py
@@ -10,7 +10,8 @@
 # or implied. See the License for the specific language governing permissions and limitations under
 # the License.
 
-import mock
+from unittest import mock
+
 import six
 
 from monasca_notification import notification as m_notification
diff --git a/tests/test_mysql_repo.py b/tests/test_mysql_repo.py
index 4e19fc7..4c08ac0 100644
--- a/tests/test_mysql_repo.py
+++ b/tests/test_mysql_repo.py
@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+from unittest import mock
 
 import pymysql
 
diff --git a/tests/test_notification_processor.py b/tests/test_notification_processor.py
index 875d110..a82916a 100644
--- a/tests/test_notification_processor.py
+++ b/tests/test_notification_processor.py
@@ -16,8 +16,8 @@
 
 """Tests NotificationProcessor"""
 
-import mock
 import time
+from unittest import mock
 
 from monasca_notification import notification as m_notification
 from monasca_notification.plugins import email_notifier
diff --git a/tests/test_notifiers.py b/tests/test_notifiers.py
index 7367606..ad3be2a 100644
--- a/tests/test_notifiers.py
+++ b/tests/test_notifiers.py
@@ -15,8 +15,8 @@
 # limitations under the License.
 
 import contextlib
-import mock
 import time
+from unittest import mock
 
 from monasca_notification import notification as m_notification
 from monasca_notification.plugins import email_notifier
diff --git a/tests/test_orm_repo.py b/tests/test_orm_repo.py
index 383287a..c610436 100644
--- a/tests/test_orm_repo.py
+++ b/tests/test_orm_repo.py
@@ -10,7 +10,7 @@
 # or implied. See the License for the specific language governing permissions and limitations under
 # the License.
 
-import mock
+from unittest import mock
 
 from monasca_notification.common.repositories.orm import orm_repo
 from tests import base
diff --git a/tests/test_pagerduty_notification.py b/tests/test_pagerduty_notification.py
index 987e3fb..38f867d 100644
--- a/tests/test_pagerduty_notification.py
+++ b/tests/test_pagerduty_notification.py
@@ -15,9 +15,9 @@
 # limitations under the License.
 
 import json
-import mock
 import requests
 import time
+from unittest import mock
 
 import six
 
diff --git a/tests/test_slack_notification.py b/tests/test_slack_notification.py
index a5272ed..c677f23 100644
--- a/tests/test_slack_notification.py
+++ b/tests/test_slack_notification.py
@@ -12,7 +12,7 @@
 # limitations under the License.
 
 import json
-import mock
+from unittest import mock
 
 import six
 
diff --git a/tests/test_webhook_notification.py b/tests/test_webhook_notification.py
index 466b2ce..eda8d0c 100644
--- a/tests/test_webhook_notification.py
+++ b/tests/test_webhook_notification.py
@@ -14,8 +14,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
 import requests
+from unittest import mock
 
 import simplejson as json
 import six