diff --git a/openstack/common/fixture/mockpatch.py b/openstack/common/fixture/mockpatch.py
index 858e77cd0..a8ffeb370 100644
--- a/openstack/common/fixture/mockpatch.py
+++ b/openstack/common/fixture/mockpatch.py
@@ -22,14 +22,15 @@ import mock
 class PatchObject(fixtures.Fixture):
     """Deal with code around mock."""
 
-    def __init__(self, obj, attr, **kwargs):
+    def __init__(self, obj, attr, new=mock.DEFAULT, **kwargs):
         self.obj = obj
         self.attr = attr
         self.kwargs = kwargs
+        self.new = new
 
     def setUp(self):
         super(PatchObject, self).setUp()
-        _p = mock.patch.object(self.obj, self.attr, **self.kwargs)
+        _p = mock.patch.object(self.obj, self.attr, self.new, **self.kwargs)
         self.mock = _p.start()
         self.addCleanup(_p.stop)
 
@@ -38,12 +39,13 @@ class Patch(fixtures.Fixture):
 
     """Deal with code around mock.patch."""
 
-    def __init__(self, obj, **kwargs):
+    def __init__(self, obj, new=mock.DEFAULT, **kwargs):
         self.obj = obj
         self.kwargs = kwargs
+        self.new = new
 
     def setUp(self):
         super(Patch, self).setUp()
-        _p = mock.patch(self.obj, **self.kwargs)
+        _p = mock.patch(self.obj, self.new, **self.kwargs)
         self.mock = _p.start()
         self.addCleanup(_p.stop)
diff --git a/tests/unit/fixture/test_mockpatch.py b/tests/unit/fixture/test_mockpatch.py
new file mode 100644
index 000000000..11d0cae1b
--- /dev/null
+++ b/tests/unit/fixture/test_mockpatch.py
@@ -0,0 +1,53 @@
+# Copyright 2014 IBM Corp.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+
+import mock
+
+from openstack.common.fixture import mockpatch
+from tests import utils
+
+
+class Foo(object):
+    def bar(self):
+        pass
+
+
+def mocking_bar(self):
+    return 'mocked!'
+
+
+class TestMockPatch(utils.BaseTestCase):
+    def test_mock_patch_with_replacement(self):
+        self.useFixture(mockpatch.Patch('%s.Foo.bar' % (__name__),
+                                        mocking_bar))
+        instance = Foo()
+        self.assertEqual(instance.bar(), 'mocked!')
+
+    def test_mock_patch_without_replacement(self):
+        self.useFixture(mockpatch.Patch('%s.Foo.bar' % (__name__)))
+        instance = Foo()
+        self.assertIsInstance(instance.bar(), mock.MagicMock)
+
+
+class TestMockPatchObject(utils.BaseTestCase):
+    def test_mock_patch_object_with_replacement(self):
+        self.useFixture(mockpatch.PatchObject(Foo, 'bar', mocking_bar))
+        instance = Foo()
+        self.assertEqual(instance.bar(), 'mocked!')
+
+    def test_mock_patch_object_without_replacement(self):
+        self.useFixture(mockpatch.PatchObject(Foo, 'bar'))
+        instance = Foo()
+        self.assertIsInstance(instance.bar(), mock.MagicMock)