diff --git a/nova/tests/unit/test_matchers.py b/nova/tests/unit/test_matchers.py
index 7bc1ec13f44f..6cc22c39091c 100644
--- a/nova/tests/unit/test_matchers.py
+++ b/nova/tests/unit/test_matchers.py
@@ -12,6 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 from collections import OrderedDict
+import pprint
 
 import testtools
 from testtools.tests.matchers import helpers
@@ -43,7 +44,7 @@ class TestDictMatches(testtools.TestCase, helpers.TestMatchersInterface):
         ]
 
     str_examples = [
-        ("DictMatches({0})".format(matches_dict),
+        ('DictMatches(%s)' % (pprint.pformat(matches_dict)),
          matches_matcher),
         ]
 
diff --git a/tests-py3.txt b/tests-py3.txt
index ac996a1ec3c4..688d49dff262 100644
--- a/tests-py3.txt
+++ b/tests-py3.txt
@@ -10,7 +10,6 @@ nova.tests.unit.compute.test_compute.ComputeAPITestCase.test_create_with_base64_
 nova.tests.unit.compute.test_compute_cells.CellsComputeAPITestCase.test_create_with_base64_user_data
 nova.tests.unit.compute.test_compute_mgr.ComputeManagerUnitTestCase.test_run_pending_deletes
 nova.tests.unit.compute.test_host_api.ComputeHostAPICellsTestCase
-nova.tests.unit.test_matchers.TestDictMatches.test__str__
 nova.tests.unit.test_wsgi.TestWSGIServerWithSSL
 nova.tests.unit.virt.libvirt.storage.test_rbd.RbdTestCase
 nova.tests.unit.virt.libvirt.test_firewall.IptablesFirewallTestCase