diff --git a/etc/emqx.conf b/etc/emqx.conf
index 94d5cbecb..098c908d0 100644
--- a/etc/emqx.conf
+++ b/etc/emqx.conf
@@ -1472,7 +1472,7 @@ listener.ssl.external.certfile = {{ platform_etc_dir }}/certs/cert.pem
 ## are used during server authentication and when building the client certificate chain.
 ##
 ## Value: File
-## listener.ssl.external.cacertfile = {{ platform_etc_dir }}/certs/cacert.pem
+listener.ssl.external.cacertfile = {{ platform_etc_dir }}/certs/cacert.pem
 
 ## The Ephemeral Diffie-Helman key exchange is a very effective way of
 ## ensuring Forward Secrecy by exchanging a set of keys that never hit