diff --git a/include/emqttd_protocol.hrl b/include/emqttd_protocol.hrl
index ee7b553d9..a335e8de7 100644
--- a/include/emqttd_protocol.hrl
+++ b/include/emqttd_protocol.hrl
@@ -40,14 +40,17 @@
 %%------------------------------------------------------------------------------
 %% MQTT QoS
 %%------------------------------------------------------------------------------
-
 -define(QOS_0, 0). %% At most once
 -define(QOS_1, 1). %% At least once
 -define(QOS_2, 2). %% Exactly once
 
--define(IS_QOS(I), (I >= ?QOS_0 andalso I =< ?QOS_2)).
+-define(QOS0, 0). %% At most once
+-define(QOS1, 1). %% At least once
+-define(QOS2, 2). %% Exactly once
 
--type mqtt_qos() :: ?QOS_0 | ?QOS_1 | ?QOS_2.
+-define(IS_QOS(I), (I >= ?QOS0 andalso I =< ?QOS2)).
+
+-type mqtt_qos() :: ?QOS0 | ?QOS1 | ?QOS2.
 
 -type mqtt_qos_name() :: qos0 | at_most_once  |
                          qos1 | at_least_once |
diff --git a/src/emqttd_pooler.erl b/src/emqttd_pooler.erl
index bec9f287a..13f4d6b8d 100644
--- a/src/emqttd_pooler.erl
+++ b/src/emqttd_pooler.erl
@@ -78,7 +78,10 @@ handle_call(_Req, _From, State) ->
     {reply, ok, State}.
 
 handle_cast({async_submit, Fun}, State) ->
-    try run(Fun) catch _:Error -> lager:error("Pooler Error: ~p", [Error]) end,
+    try run(Fun)
+    catch _:Error ->
+        lager:error("Pooler Error: ~p, ~p", [Error, erlang:get_stacktrace()])
+    end,
     {noreply, State};
 
 handle_cast(_Msg, State) ->