diff --git a/example.env b/example.env
index f1fb6742..adbf74ca 100644
--- a/example.env
+++ b/example.env
@@ -34,6 +34,7 @@ UPSTREAM_REAL_IP_HEADER=
 # is replaced by the last address sent in the request header field defined by the real_ip_header directive.
 # If recursive search is enabled, the original client address that matches one of the trusted addresses is replaced by the last non-trusted address sent in the request header field.
 UPSTREAM_REAL_IP_RECURSIVE=
+PORTS=
 
 # All Values Allowed by nginx proxy_read_timeout are allowed, default value is 120s
 # Useful if you have longrunning print formats or slow loading sites