diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index a4f89aea7b..f13272da8e 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -404,7 +404,9 @@ def _parse_json(request):
     try:
         content = json.loads(request.content.read())
         if type(content) != dict:
-            raise SynapseError(400, "Content must be a JSON object.", errcode=Codes.BAD_JSON)
+            raise SynapseError(
+                400, "Content must be a JSON object.", errcode=Codes.BAD_JSON
+            )
         return content
     except ValueError:
         raise SynapseError(400, "Content not JSON.", errcode=Codes.NOT_JSON)