diff --git a/heat/tests/test_signal.py b/heat/tests/test_signal.py
index 470843056..d6caa908e 100644
--- a/heat/tests/test_signal.py
+++ b/heat/tests/test_signal.py
@@ -211,9 +211,17 @@ class SignalTest(HeatTestCase):
             rsrc.signal(details=test_d)
 
         self.m.VerifyAll()
-        # so we don't have to stub out deletion events.
         self.m.UnsetStubs()
 
+        # Since we unset the stubs above we must re-stub keystone to keep the
+        # test isolated from keystoneclient. The unset stubs is done so that we
+        # do not have to mock out all of the deleting that the
+        # stack_delete_after decorator will do during cleanup.
+        self.m.StubOutWithMock(self.stack.clients, 'keystone')
+        self.stack.clients.keystone().AndReturn(self.fc)
+
+        self.m.ReplayAll()
+
     @utils.stack_delete_after
     def test_signal_wrong_resource(self):
         # assert that we get the correct exception when calling a