diff --git a/nixos/modules/services/mail/mail.nix b/nixos/modules/services/mail/mail.nix
index b7e1d295f2c5..63e8d78b5b02 100644
--- a/nixos/modules/services/mail/mail.nix
+++ b/nixos/modules/services/mail/mail.nix
@@ -12,9 +12,9 @@ with lib;
 
       sendmailSetuidWrapper = mkOption {
         default = null;
+        internal = true;
         description = ''
-          Configuration for the sendmail setuid wrwapper (like an element of
-          security.setuidOwners)";
+          Configuration for the sendmail setuid wapper.
         '';
       };