diff --git a/refstack/tests/api/test_products.py b/refstack/tests/api/test_products.py
index 0a66982e..c53e5ae6 100644
--- a/refstack/tests/api/test_products.py
+++ b/refstack/tests/api/test_products.py
@@ -14,8 +14,8 @@
 
 import json
 import uuid
+from unittest import mock
 
-import mock
 from oslo_config import fixture as config_fixture
 import webtest.app
 
diff --git a/refstack/tests/api/test_profile.py b/refstack/tests/api/test_profile.py
index 35bda032..4532c483 100644
--- a/refstack/tests/api/test_profile.py
+++ b/refstack/tests/api/test_profile.py
@@ -14,13 +14,13 @@
 
 import binascii
 import json
+from unittest import mock
 
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives.asymmetric import padding
 from cryptography.hazmat.primitives.asymmetric import rsa
 from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives import serialization
-import mock
 import webtest.app
 
 from refstack.tests import api
diff --git a/refstack/tests/api/test_results.py b/refstack/tests/api/test_results.py
index 27ebc9ec..612df64c 100644
--- a/refstack/tests/api/test_results.py
+++ b/refstack/tests/api/test_results.py
@@ -14,8 +14,8 @@
 
 import json
 import uuid
+from unittest import mock
 
-import mock
 from oslo_config import fixture as config_fixture
 import webtest.app
 
diff --git a/refstack/tests/api/test_vendors.py b/refstack/tests/api/test_vendors.py
index 3bf4ef56..d6ae0150 100644
--- a/refstack/tests/api/test_vendors.py
+++ b/refstack/tests/api/test_vendors.py
@@ -14,8 +14,8 @@
 
 import json
 import uuid
+from unittest import mock
 
-import mock
 from oslo_config import fixture as config_fixture
 import webtest.app
 
diff --git a/refstack/tests/unit/__init__.py b/refstack/tests/unit/__init__.py
index 52c07604..59639526 100644
--- a/refstack/tests/unit/__init__.py
+++ b/refstack/tests/unit/__init__.py
@@ -14,8 +14,8 @@
 #    under the License.
 """Refstack unittests."""
 
-import mock
 from oslotest import base
+from unittest import mock
 
 
 class RefstackBaseTestCase(base.BaseTestCase):
diff --git a/refstack/tests/unit/test_api.py b/refstack/tests/unit/test_api.py
index b2f14fba..bff25458 100644
--- a/refstack/tests/unit/test_api.py
+++ b/refstack/tests/unit/test_api.py
@@ -16,8 +16,8 @@
 """Tests for API's controllers"""
 
 import json
+from unittest import mock
 
-import mock
 from oslo_config import fixture as config_fixture
 from urllib import parse
 import webob.exc
diff --git a/refstack/tests/unit/test_api_utils.py b/refstack/tests/unit/test_api_utils.py
index 72f0ff63..992ef34e 100644
--- a/refstack/tests/unit/test_api_utils.py
+++ b/refstack/tests/unit/test_api_utils.py
@@ -15,8 +15,8 @@
 
 """Tests for API's utils"""
 import time
+from unittest import mock
 
-import mock
 from oslo_config import fixture as config_fixture
 from oslo_utils import timeutils
 from oslotest import base
diff --git a/refstack/tests/unit/test_app.py b/refstack/tests/unit/test_app.py
index aebd41f8..e407ceb2 100644
--- a/refstack/tests/unit/test_app.py
+++ b/refstack/tests/unit/test_app.py
@@ -16,8 +16,8 @@
 """Tests for API's utility"""
 
 import json
+from unittest import mock
 
-import mock
 from oslo_config import fixture as config_fixture
 from oslotest import base
 import pecan
diff --git a/refstack/tests/unit/test_db.py b/refstack/tests/unit/test_db.py
index 4ea9eb77..39325d9b 100644
--- a/refstack/tests/unit/test_db.py
+++ b/refstack/tests/unit/test_db.py
@@ -17,7 +17,8 @@
 
 import base64
 import hashlib
-import mock
+from unittest import mock
+
 from oslo_config import fixture as config_fixture
 from oslotest import base
 import sqlalchemy.orm
diff --git a/refstack/tests/unit/test_guidelines.py b/refstack/tests/unit/test_guidelines.py
index b27c4831..a0b792e7 100644
--- a/refstack/tests/unit/test_guidelines.py
+++ b/refstack/tests/unit/test_guidelines.py
@@ -14,9 +14,9 @@
 #    under the License.
 
 import json
+from unittest import mock
 
 import httmock
-import mock
 from oslotest import base
 import requests
 
diff --git a/refstack/tests/unit/test_migration.py b/refstack/tests/unit/test_migration.py
index 29942226..99faaa42 100644
--- a/refstack/tests/unit/test_migration.py
+++ b/refstack/tests/unit/test_migration.py
@@ -16,7 +16,7 @@
 """Tests for refstack's migrations."""
 
 import alembic
-import mock
+from unittest import mock
 from oslotest import base
 
 from refstack.db import migration
diff --git a/refstack/tests/unit/test_validators.py b/refstack/tests/unit/test_validators.py
index 976b3d1b..b9d64e45 100644
--- a/refstack/tests/unit/test_validators.py
+++ b/refstack/tests/unit/test_validators.py
@@ -16,6 +16,7 @@
 """Tests for validators."""
 import binascii
 import json
+from unittest import mock
 
 from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives.asymmetric import padding
@@ -24,7 +25,6 @@ from cryptography.hazmat.primitives import hashes
 from cryptography.hazmat.primitives import serialization
 
 import jsonschema
-import mock
 from oslotest import base
 
 from refstack.api import exceptions as api_exc
diff --git a/test-requirements.txt b/test-requirements.txt
index f7f07a23..e5f32af4 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -4,7 +4,6 @@ pyflakes==0.8.1
 flake8==2.2.4
 docutils>=0.11  # OSI-Approved Open Source, Public Domain
 httmock>=1.2.4
-mock
 oslotest>=1.2.0 # Apache-2.0
 python-subunit>=0.0.18
 stestr>=1.1.0 # Apache-2.0