diff --git a/etc/emq.conf b/etc/emq.conf
index 8c155882f..5fb004b12 100644
--- a/etc/emq.conf
+++ b/etc/emq.conf
@@ -191,7 +191,7 @@ mqtt.mqueue.type = simple
 
 ## Max queue length. Enqueued messages when persistent client disconnected,
 ## or inflight window is full. 0 means no limit.
-mqtt.mqueue.max_length = 0
+mqtt.mqueue.max_length = 1000
 
 ## Low-water mark of queued messages
 mqtt.mqueue.low_watermark = 20%