diff --git a/core/assets/scaffold/files/default.settings.php b/core/assets/scaffold/files/default.settings.php
index 827b6555e93..5615be3dc0b 100644
--- a/core/assets/scaffold/files/default.settings.php
+++ b/core/assets/scaffold/files/default.settings.php
@@ -358,10 +358,13 @@ $settings['update_free_access'] = FALSE;
 # $settings['reverse_proxy'] = TRUE;
 
 /**
- * Specify every reverse proxy IP address in your environment.
- * This setting is required if $settings['reverse_proxy'] is TRUE.
+ * Reverse proxy addresses.
+ *
+ * Specify every reverse proxy IP address in your environment, as an array of
+ * IPv4/IPv6 addresses or subnets in CIDR notation. This setting is required if
+ * $settings['reverse_proxy'] is TRUE.
  */
-# $settings['reverse_proxy_addresses'] = ['a.b.c.d', ...];
+# $settings['reverse_proxy_addresses'] = ['a.b.c.d', 'e.f.g.h/24', ...];
 
 /**
  * Reverse proxy trusted headers.
diff --git a/sites/default/default.settings.php b/sites/default/default.settings.php
index 827b6555e93..5615be3dc0b 100644
--- a/sites/default/default.settings.php
+++ b/sites/default/default.settings.php
@@ -358,10 +358,13 @@ $settings['update_free_access'] = FALSE;
 # $settings['reverse_proxy'] = TRUE;
 
 /**
- * Specify every reverse proxy IP address in your environment.
- * This setting is required if $settings['reverse_proxy'] is TRUE.
+ * Reverse proxy addresses.
+ *
+ * Specify every reverse proxy IP address in your environment, as an array of
+ * IPv4/IPv6 addresses or subnets in CIDR notation. This setting is required if
+ * $settings['reverse_proxy'] is TRUE.
  */
-# $settings['reverse_proxy_addresses'] = ['a.b.c.d', ...];
+# $settings['reverse_proxy_addresses'] = ['a.b.c.d', 'e.f.g.h/24', ...];
 
 /**
  * Reverse proxy trusted headers.