diff -r -U3 fasteners-0.14.1-orig/fasteners/test.py fasteners-0.14.1/fasteners/test.py
--- fasteners-0.14.1-orig/fasteners/test.py	2015-11-13 07:46:46.000000000 +0100
+++ fasteners-0.14.1/fasteners/test.py	2018-06-19 13:38:10.956742064 +0200
@@ -16,8 +16,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import testtools
+import unittest
 
 
-class TestCase(testtools.TestCase):
+class TestCase(unittest.TestCase):
     pass