diff --git a/etc/emqx.conf b/etc/emqx.conf
index 41ac298fa..cb6e91b96 100644
--- a/etc/emqx.conf
+++ b/etc/emqx.conf
@@ -500,6 +500,17 @@ mqtt.wildcard_subscription = true
 ## Value: boolean
 mqtt.shared_subscription = true
 
+## Message queue type.
+##
+## Value: simple | priority
+mqtt.mqueue_type = simple
+
+## Topic priorities. Default is 0.
+##
+## Priority: Number [0-255]
+##
+## mqtt.mqueue_priorities = topic/1=10,topic/2=8
+
 ##--------------------------------------------------------------------
 ## Zones
 ##--------------------------------------------------------------------
@@ -616,12 +627,23 @@ zone.external.await_rel_timeout = 60s
 ## Default: 2h, 2 hours
 zone.external.session_expiry_interval = 2h
 
+## Message queue type.
+##
+## Value: simple | priority
+zone.external.mqueue_type = simple
+
 ## Maximum queue length. Enqueued messages when persistent client disconnected,
 ## or inflight window is full. 0 means no limit.
 ##
 ## Value: Number >= 0
 zone.external.max_mqueue_len = 1000
 
+## Topic priorities. Default is 0.
+##
+## Priority: Number [0-255]
+##
+## zone.external.mqueue_priorities = topic/1=10,topic/2=8
+
 ## Whether to enqueue Qos0 messages.
 ##
 ## Value: false | true