1 files changed, 1 insertions, 0 deletions
diff --git a/synapse/rest/client/register.py b/synapse/rest/client/register.py
index 3cb1e7e375..be696c304b 100644
--- a/synapse/rest/client/register.py
+++ b/synapse/rest/client/register.py
@@ -310,6 +310,7 @@ class UsernameAvailabilityRestServlet(RestServlet):
         self.hs = hs
         self.registration_handler = hs.get_registration_handler()
         self.ratelimiter = FederationRateLimiter(
+            hs.get_reactor(),
             hs.get_clock(),
             FederationRatelimitSettings(
                 # Time window of 2s