diff --git a/keystoneclient/tests/v3/test_trusts.py b/keystoneclient/tests/v3/test_trusts.py
index 43bfb1b53..15e934888 100644
--- a/keystoneclient/tests/v3/test_trusts.py
+++ b/keystoneclient/tests/v3/test_trusts.py
@@ -105,4 +105,4 @@ class TrustTests(utils.TestCase, utils.CrudTests):
 
     def test_update(self):
         # Update not supported for the OS-TRUST API
-        self.assertRaises(exceptions.HttpNotImplemented, self.manager.update)
+        self.assertRaises(exceptions.MethodNotImplemented, self.manager.update)
diff --git a/keystoneclient/v3/contrib/trusts.py b/keystoneclient/v3/contrib/trusts.py
index 9336b1e0a..ed199e6ed 100644
--- a/keystoneclient/v3/contrib/trusts.py
+++ b/keystoneclient/v3/contrib/trusts.py
@@ -74,7 +74,8 @@ class TrustManager(base.CrudManager):
             **kwargs)
 
     def update(self):
-        raise exceptions.HttpNotImplemented("Update not supported for trusts")
+        raise exceptions.MethodNotImplemented('Update not supported'
+                                              ' for trusts')
 
     def list(self, trustee_user=None, trustor_user=None, **kwargs):
         """List Trusts."""