diff --git a/blazarclient/tests/test_base.py b/blazarclient/tests/test_base.py
index 32f8d67..f04bb6b 100644
--- a/blazarclient/tests/test_base.py
+++ b/blazarclient/tests/test_base.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 
 
-import mock
+from unittest import mock
 
 from blazarclient import base
 from blazarclient import exception
diff --git a/blazarclient/tests/test_command.py b/blazarclient/tests/test_command.py
index a03873b..f8091aa 100644
--- a/blazarclient/tests/test_command.py
+++ b/blazarclient/tests/test_command.py
@@ -13,7 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import mock
+from unittest import mock
+
 import testtools
 
 from blazarclient import command
diff --git a/blazarclient/tests/v1/shell_commands/test_floatingips.py b/blazarclient/tests/v1/shell_commands/test_floatingips.py
index 5816742..65b685a 100644
--- a/blazarclient/tests/v1/shell_commands/test_floatingips.py
+++ b/blazarclient/tests/v1/shell_commands/test_floatingips.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 
 import argparse
-import mock
+from unittest import mock
 
 from blazarclient import shell
 from blazarclient import tests
diff --git a/blazarclient/tests/v1/shell_commands/test_hosts.py b/blazarclient/tests/v1/shell_commands/test_hosts.py
index 611ed7d..1dac190 100644
--- a/blazarclient/tests/v1/shell_commands/test_hosts.py
+++ b/blazarclient/tests/v1/shell_commands/test_hosts.py
@@ -14,7 +14,7 @@
 # limitations under the License.
 
 import argparse
-import mock
+from unittest import mock
 
 from blazarclient import shell
 from blazarclient import tests
diff --git a/blazarclient/tests/v1/shell_commands/test_leases.py b/blazarclient/tests/v1/shell_commands/test_leases.py
index c90728c..8355315 100644
--- a/blazarclient/tests/v1/shell_commands/test_leases.py
+++ b/blazarclient/tests/v1/shell_commands/test_leases.py
@@ -15,7 +15,7 @@
 
 import argparse
 from datetime import datetime
-import mock
+from unittest import mock
 
 from blazarclient import exception
 from blazarclient import shell
diff --git a/lower-constraints.txt b/lower-constraints.txt
index da9bdcd..0da54d6 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -9,7 +9,6 @@ fixtures==3.0.0
 iso8601==0.1.11
 keystoneauth1==3.4.0
 linecache2==1.0.0
-mock==3.0.0
 monotonic==0.6
 mox3==0.20.0
 msgpack-python==0.4.0
diff --git a/test-requirements.txt b/test-requirements.txt
index 94950ea..636c742 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -7,7 +7,6 @@ hacking>=1.1.0,<3.0.1 # Apache-2.0
 # care of pyflakes version compatibilty.
 pyflakes>=2.1.1
 
-mock>=3.0.0 # BSD
 oslotest>=3.2.0 # Apache-2.0
 fixtures>=3.0.0 # Apache-2.0/BSD
 testrepository>=0.0.18 # Apache-2.0/BSD