diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 380bf294e..cdeb3792b 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -190,12 +190,11 @@ class MatrixFederationHttpClient(object):
 
     @defer.inlineCallbacks
     def _send_request_with_optional_trailing_slash(
-        self,
-        request,
-        try_trailing_slash_on_400=False,
-        backoff_on_404=False,
-        **kwargs,
-    ):
+            self,
+            request,
+            try_trailing_slash_on_400=False,
+            backoff_on_404=False,
+            **kwargs):
         """Wrapper for _send_request which can optionally retry the request
         upon receiving a combination of a 400 HTTP response code and a
         'M_UNRECOGNIZED' errcode. This is a workaround for Synapse <=v0.99.2