diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index b2806555c..2052d6d05 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -719,7 +719,9 @@ class RoomMemberHandler(BaseHandler):
         )
         membership = member.membership if member else None
 
-        if membership is not None and membership != Membership.LEAVE:
+        if membership is not None and membership not in [
+            Membership.LEAVE, Membership.BAN
+        ]:
             raise SynapseError(400, "User %s in room %s" % (
                 user_id, room_id
             ))