diff --git a/include/emqttd_protocol.hrl b/include/emqttd_protocol.hrl
index ab0650ead..a7eb768e3 100644
--- a/include/emqttd_protocol.hrl
+++ b/include/emqttd_protocol.hrl
@@ -129,11 +129,16 @@
 
 -type(mqtt_connack() :: ?CONNACK_ACCEPT..?CONNACK_AUTH).
 
+%%--------------------------------------------------------------------
+%% Max MQTT Packet Length
+%%--------------------------------------------------------------------
+
+-define(MAX_PACKET_LEN, 16#fffffff).
+
 %%--------------------------------------------------------------------
 %% MQTT Parser and Serializer
 %%--------------------------------------------------------------------
 
--define(MAX_LEN, 16#fffffff).
 -define(HIGHBIT, 2#10000000).
 -define(LOWBITS, 2#01111111).