Index: pbr-5.5.1/pbr/tests/test_packaging.py
===================================================================
--- pbr-5.5.1.orig/pbr/tests/test_packaging.py
+++ pbr-5.5.1/pbr/tests/test_packaging.py
@@ -48,7 +48,10 @@ import tempfile
 import textwrap
 
 import fixtures
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 import pkg_resources
 import six
 import testscenarios
Index: pbr-5.5.1/pbr/tests/test_pbr_json.py
===================================================================
--- pbr-5.5.1.orig/pbr/tests/test_pbr_json.py
+++ pbr-5.5.1/pbr/tests/test_pbr_json.py
@@ -10,7 +10,10 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-import mock
+try:
+    from unittest import mock
+except ImportError:
+    import mock
 
 from pbr import pbr_json
 from pbr.tests import base
Index: pbr-5.5.1/test-requirements.txt
===================================================================
--- pbr-5.5.1.orig/test-requirements.txt
+++ pbr-5.5.1/test-requirements.txt
@@ -5,7 +5,7 @@
 wheel>=0.32.0 # MIT
 fixtures>=3.0.0 # Apache-2.0/BSD
 hacking>=1.1.0,<4.0.0 # Apache-2.0
-mock>=2.0.0 # BSD
+mock>=2.0.0;python_version<='3.3' # BSD
 six>=1.12.0 # MIT
 stestr>=2.1.0,<3.0;python_version=='2.7' # Apache-2.0
 stestr>=2.1.0;python_version>='3.0' # Apache-2.0