diff --git a/tempest/exceptions.py b/tempest/exceptions.py
index de22688..6b9ce74 100644
--- a/tempest/exceptions.py
+++ b/tempest/exceptions.py
@@ -15,7 +15,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import unittest2 as unittest
+import testtools
 
 
 class TempestException(Exception):
@@ -53,7 +53,7 @@
 
 
 class RestClientException(TempestException,
-                          unittest.TestCase.failureException):
+                          testtools.TestCase.failureException):
     pass