diff --git a/src/emqtt_client.erl b/src/emqtt_client.erl
index ee3085cbf..336920577 100644
--- a/src/emqtt_client.erl
+++ b/src/emqtt_client.erl
@@ -179,6 +179,7 @@ process_received_bytes(<<>>, State) ->
 process_received_bytes(Bytes,
                        State = #state{ parse_state = ParseState,
                                        conn_name   = ConnStr }) ->
+	?INFO("~p~n", [Bytes]),
     case emqtt_frame:parse(Bytes, ParseState) of
 	{more, ParseState1} ->
 		{noreply,
@@ -434,12 +435,17 @@ validate_frame(?PUBLISH, #mqtt_frame{variable = #mqtt_frame_publish{topic_name =
 	false -> {error, badtopic}
 	end;
 
-validate_frame(?UNSUBSCRIBE, Frame) ->
-	validate_frame(?SUBSCRIBE, Frame);
+validate_frame(?UNSUBSCRIBE, #mqtt_frame{variable = #mqtt_frame_subscribe{topic_table = Topics}}) ->
+	ErrTopics = [Topic || #mqtt_topic{name=Topic, qos=Qos} <- Topics,
+						not emqtt_topic:validate({subscribe, Topic})],
+	case ErrTopics of
+	[] -> ok;
+	_ -> ?ERROR("error topics: ~p", [ErrTopics]), {error, badtopic}
+	end;
 
 validate_frame(?SUBSCRIBE, #mqtt_frame{variable = #mqtt_frame_subscribe{topic_table = Topics}}) ->
-	ErrTopics = [Topic || #mqtt_topic{name=Topic} <- Topics,
-						not emqtt_topic:validate({subscribe, Topic})],
+	ErrTopics = [Topic || #mqtt_topic{name=Topic, qos=Qos} <- Topics,
+						not (emqtt_topic:validate({subscribe, Topic}) and (Qos < 3))],
 	case ErrTopics of
 	[] -> ok;
 	_ -> ?ERROR("error topics: ~p", [ErrTopics]), {error, badtopic}