diff --git a/lib/Constants.php b/lib/Constants.php
index 0d02e8256..0d53a168a 100644
--- a/lib/Constants.php
+++ b/lib/Constants.php
@@ -39,6 +39,7 @@ class Constants {
 		self::CONFIG_KEY_ALLOWCONFIRMATIONEMAIL => 'bool',
 		self::CONFIG_KEY_CREATIONALLOWEDGROUPS => 'array',
 		self::CONFIG_KEY_CONFIRMATIONEMAILRATELIMIT => 'int',
+		self::CONFIG_KEY_ALLOWCOMMENTS => 'bool',
 	];
 
 	/**