diff --git a/taskflow/test.py b/taskflow/test.py
index a9cce357b..a5d880a85 100644
--- a/taskflow/test.py
+++ b/taskflow/test.py
@@ -16,9 +16,9 @@
 
 import collections
 import logging
+from unittest import mock
 
 import fixtures
-import mock
 from oslotest import base
 import six
 
diff --git a/taskflow/tests/unit/worker_based/test_proxy.py b/taskflow/tests/unit/worker_based/test_proxy.py
index 68688fa21..c9574334e 100644
--- a/taskflow/tests/unit/worker_based/test_proxy.py
+++ b/taskflow/tests/unit/worker_based/test_proxy.py
@@ -15,10 +15,10 @@
 #    under the License.
 
 import socket
+from unittest import mock
 
 from taskflow.engines.worker_based import proxy
 from taskflow import test
-from taskflow.test import mock
 from taskflow.utils import threading_utils
 
 
diff --git a/test-requirements.txt b/test-requirements.txt
index def4e68ad..5a4405193 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -26,7 +26,6 @@ psycopg2>=2.8.0 # LGPL/ZPL
 pydotplus>=2.0.2 # MIT License
 hacking<2.1,>=2.0
 oslotest>=3.2.0 # Apache-2.0
-mock>=2.0.0 # BSD
 testtools>=2.2.0 # MIT
 testscenarios>=0.4 # Apache-2.0/BSD
 stestr>=2.0.0 # Apache-2.0
diff --git a/tools/state_graph.py b/tools/state_graph.py
index 9b086382c..cc70fb2a7 100755
--- a/tools/state_graph.py
+++ b/tools/state_graph.py
@@ -14,7 +14,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import mock
+from unittest import mock
 
 import optparse
 import os