diff --git a/etc/emq.conf b/etc/emq.conf
index 13be72968..3bcadfaf8 100644
--- a/etc/emq.conf
+++ b/etc/emq.conf
@@ -704,7 +704,7 @@ listener.tcp.external.send_timeout_close = on
 ## Sets the 'buffer = max(sndbuf, recbuf)' if this option is enabled.
 ##
 ## Value: on | off
-listener.tcp.external.tune_buffer = on
+## listener.tcp.external.tune_buffer = off
 
 ## The TCP_NODELAY flag for MQTT connections. Small amounts of data are
 ## sent immediately if the option is enabled.
@@ -783,28 +783,28 @@ listener.tcp.external.send_timeout_close = on
 ## See: listener.tcp.<name>.recbuf
 ##
 ## Value: Bytes
-listener.tcp.internal.recbuf = 16KB
+## listener.tcp.internal.recbuf = 16KB
 
 ## The TCP send buffer(os kernel) for internal MQTT connections.
 ##
 ## See: http://erlang.org/doc/man/inet.html
 ##
 ## Value: Bytes
-listener.tcp.internal.sndbuf = 16KB
+## listener.tcp.internal.sndbuf = 16KB
 
 ## The size of the user-level software buffer used by the driver.
 ##
 ## See: listener.tcp.<name>.buffer
 ##
 ## Value: Bytes
-listener.tcp.internal.buffer = 16KB
+## listener.tcp.internal.buffer = 16KB
 
 ## Sets the 'buffer = max(sndbuf, recbuf)' if this option is enabled.
 ##
 ## See: listener.tcp.<name>.tune_buffer
 ##
 ## Value: on | off
-listener.tcp.internal.tune_buffer = on
+## listener.tcp.internal.tune_buffer = off
 
 ## The TCP_NODELAY flag for internal MQTT connections.
 ##
@@ -1038,7 +1038,7 @@ listener.ssl.external.certfile = {{ platform_etc_dir }}/certs/cert.pem
 ## See: listener.tcp.<name>.tune_buffer
 ##
 ## Value: on | off
-## listener.ssl.external.tune_buffer = on
+## listener.ssl.external.tune_buffer = off
 
 ## The TCP_NODELAY flag for SSL connections.
 ##
@@ -1166,7 +1166,7 @@ listener.ws.external.send_timeout_close = on
 ## See: listener.tcp.<name>.tune_buffer
 ##
 ## Value: on | off
-listener.ws.external.tune_buffer = on
+## listener.ws.external.tune_buffer = off
 
 ## The TCP_NODELAY flag for external MQTT/WebSocket connections.
 ##