diff --git a/nixos/modules/services/mail/postfix.nix b/nixos/modules/services/mail/postfix.nix
index e8b5f832e66e..209e066a19ef 100644
--- a/nixos/modules/services/mail/postfix.nix
+++ b/nixos/modules/services/mail/postfix.nix
@@ -747,7 +747,7 @@ in
 
             ${concatStringsSep "\n" (mapAttrsToList (to: from: ''
               ln -sf ${from} /var/lib/postfix/conf/${to}
-              ${pkgs.postfix}/bin/postalias /var/lib/postfix/conf/${to}
+              ${pkgs.postfix}/bin/postalias -o -p /var/lib/postfix/conf/${to}
             '') cfg.aliasFiles)}
             ${concatStringsSep "\n" (mapAttrsToList (to: from: ''
               ln -sf ${from} /var/lib/postfix/conf/${to}