diff --git a/keystone/tests/unit/common/test_base64utils.py b/keystone/tests/unit/common/test_base64utils.py
index cec401407d..b0b75578e8 100644
--- a/keystone/tests/unit/common/test_base64utils.py
+++ b/keystone/tests/unit/common/test_base64utils.py
@@ -26,7 +26,7 @@ base64url_alphabet = ('ABCDEFGHIJKLMNOPQRSTUVWXYZ'
                       '-_=')    # includes pad char
 
 
-class TestValid(tests.TestCase):
+class TestValid(tests.BaseTestCase):
     def test_valid_base64(self):
         self.assertTrue(base64utils.is_valid_base64('+/=='))
         self.assertTrue(base64utils.is_valid_base64('+/+='))
@@ -68,7 +68,7 @@ class TestValid(tests.TestCase):
         self.assertTrue(base64utils.is_valid_base64url('-_=='))
 
 
-class TestBase64Padding(tests.TestCase):
+class TestBase64Padding(tests.BaseTestCase):
 
     def test_filter(self):
         self.assertEqual('', base64utils.filter_formatting(''))
@@ -189,7 +189,7 @@ class TestBase64Padding(tests.TestCase):
                           base64utils.base64url_percent_decode, 'AB%3D%3')
 
 
-class TestTextWrap(tests.TestCase):
+class TestTextWrap(tests.BaseTestCase):
 
     def test_wrapping(self):
         raw_text = 'abcdefgh'
diff --git a/keystone/tests/unit/common/test_pemutils.py b/keystone/tests/unit/common/test_pemutils.py
index dd00d9e220..c2f585186c 100644
--- a/keystone/tests/unit/common/test_pemutils.py
+++ b/keystone/tests/unit/common/test_pemutils.py
@@ -66,7 +66,7 @@ class PEM(object):
         self.pem_text = make_pem(self.pem_header, self.data)
 
 
-class TestPEMParseResult(tests.TestCase):
+class TestPEMParseResult(tests.BaseTestCase):
 
     def test_pem_types(self):
         for pem_type in pemutils.pem_types:
@@ -91,7 +91,7 @@ class TestPEMParseResult(tests.TestCase):
                           pemutils.PEMParseResult, pem_header=pem_header)
 
 
-class TestPEMParse(tests.TestCase):
+class TestPEMParse(tests.BaseTestCase):
     def test_parse_none(self):
         text = ''
         text += 'bla bla\n'
diff --git a/keystone/tests/unit/common/test_utils.py b/keystone/tests/unit/common/test_utils.py
index 5cc4a53651..184c814165 100644
--- a/keystone/tests/unit/common/test_utils.py
+++ b/keystone/tests/unit/common/test_utils.py
@@ -14,6 +14,7 @@ import datetime
 import uuid
 
 from oslo_config import cfg
+from oslo_config import fixture as config_fixture
 from oslo_serialization import jsonutils
 
 from keystone.common import utils as common_utils
@@ -28,9 +29,13 @@ CONF = cfg.CONF
 TZ = utils.TZ
 
 
-class UtilsTestCase(tests.TestCase):
+class UtilsTestCase(tests.BaseTestCase):
     OPTIONAL = object()
 
+    def setUp(self):
+        super(UtilsTestCase, self).setUp()
+        self.config_fixture = self.useFixture(config_fixture.Config(CONF))
+
     def test_hash(self):
         password = 'right'
         wrong = 'wrongwrong'  # Two wrongs don't make a right
@@ -149,7 +154,7 @@ class UtilsTestCase(tests.TestCase):
         self.assertEqual(expected_json, json)
 
 
-class ServiceHelperTests(tests.TestCase):
+class ServiceHelperTests(tests.BaseTestCase):
 
     @service.fail_gracefully
     def _do_test(self):
diff --git a/keystone/tests/unit/test_exception.py b/keystone/tests/unit/test_exception.py
index f056eed5d8..f91fa2a737 100644
--- a/keystone/tests/unit/test_exception.py
+++ b/keystone/tests/unit/test_exception.py
@@ -14,6 +14,8 @@
 
 import uuid
 
+from oslo_config import cfg
+from oslo_config import fixture as config_fixture
 from oslo_serialization import jsonutils
 import six
 
@@ -22,7 +24,7 @@ from keystone import exception
 from keystone.tests import unit as tests
 
 
-class ExceptionTestCase(tests.TestCase):
+class ExceptionTestCase(tests.BaseTestCase):
     def assertValidJsonRendering(self, e):
         resp = wsgi.render_exception(e)
         self.assertEqual(e.code, resp.status_int)
@@ -105,6 +107,7 @@ class UnexpectedExceptionTestCase(ExceptionTestCase):
     def setUp(self):
         super(UnexpectedExceptionTestCase, self).setUp()
         self.exc_str = uuid.uuid4().hex
+        self.config_fixture = self.useFixture(config_fixture.Config(cfg.CONF))
 
     def test_unexpected_error_no_debug(self):
         self.config_fixture.config(debug=False)
@@ -151,6 +154,11 @@ class UnexpectedExceptionTestCase(ExceptionTestCase):
 
 class SecurityErrorTestCase(ExceptionTestCase):
     """Tests whether security-related info is exposed to the API user."""
+
+    def setUp(self):
+        super(SecurityErrorTestCase, self).setUp()
+        self.config_fixture = self.useFixture(config_fixture.Config(cfg.CONF))
+
     def test_unauthorized_exposure(self):
         self.config_fixture.config(debug=False)
 
diff --git a/keystone/tests/unit/token/test_provider.py b/keystone/tests/unit/token/test_provider.py
index 5282bebc0b..e5910690c2 100644
--- a/keystone/tests/unit/token/test_provider.py
+++ b/keystone/tests/unit/token/test_provider.py
@@ -16,7 +16,7 @@ from keystone.tests import unit
 from keystone.token import provider
 
 
-class TestRandomStrings(unit.TestCase):
+class TestRandomStrings(unit.BaseTestCase):
     def test_strings_are_url_safe(self):
         s = provider.random_urlsafe_str()
         self.assertEqual(s, urllib.quote_plus(s))