diff --git a/src/ejabberd_s2s.erl b/src/ejabberd_s2s.erl
index 14c1de9dc..02a6c49d9 100644
--- a/src/ejabberd_s2s.erl
+++ b/src/ejabberd_s2s.erl
@@ -266,6 +266,7 @@ find_connection(From, To) ->
     end.
 
 choose_connection(From, Connections) ->
+    % use sticky connections based on the full JID of the sender
     El = lists:nth(erlang:phash(From, length(Connections)), Connections),
     %El = lists:nth(random:uniform(length(Connections)), Connections),
     ?ERROR_MSG("XXX using ejabberd_s2s_out ~p~n", [El#s2s.pid]),