diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index 54e3434928..f03ee1476b 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -534,4 +534,3 @@ class RegistrationHandler(BaseHandler):
             remote_room_hosts=remote_room_hosts,
             action="join",
         )
-
diff --git a/tests/handlers/test_register.py b/tests/handlers/test_register.py
index a821da0750..6699d25121 100644
--- a/tests/handlers/test_register.py
+++ b/tests/handlers/test_register.py
@@ -17,7 +17,7 @@ from mock import Mock
 
 from twisted.internet import defer
 
-from synapse.api.errors import RegistrationError
+from synapse.api.errors import AuthError
 from synapse.handlers.register import RegistrationHandler
 from synapse.types import UserID, create_requester
 
@@ -109,7 +109,7 @@ class RegistrationTestCase(unittest.TestCase):
         self.store.get_monthly_active_count = Mock(
             return_value=defer.succeed(self.lots_of_users)
         )
-        with self.assertRaises(RegistrationError):
+        with self.assertRaises(AuthError):
             yield self.handler.get_or_create_user("requester", 'b', "display_name")
 
     @defer.inlineCallbacks
@@ -118,7 +118,7 @@ class RegistrationTestCase(unittest.TestCase):
         self.store.get_monthly_active_count = Mock(
             return_value=defer.succeed(self.lots_of_users)
         )
-        with self.assertRaises(RegistrationError):
+        with self.assertRaises(AuthError):
             yield self.handler.register(localpart="local_part")
 
         self.store.get_monthly_active_count = Mock(
@@ -133,5 +133,5 @@ class RegistrationTestCase(unittest.TestCase):
         self.store.get_monthly_active_count = Mock(
             return_value=defer.succeed(self.lots_of_users)
         )
-        with self.assertRaises(RegistrationError):
+        with self.assertRaises(AuthError):
             yield self.handler.register_saml2(localpart="local_part")