diff --git a/nixos/modules/security/acme.nix b/nixos/modules/security/acme.nix
index 3d25e811e670..c5cd0fb60ee9 100644
--- a/nixos/modules/security/acme.nix
+++ b/nixos/modules/security/acme.nix
@@ -56,7 +56,7 @@ let
 
       plugins = mkOption {
         type = types.listOf (types.enum [
-          "cert.der" "cert.pem" "chain.pem" "external_pem.sh"
+          "cert.der" "cert.pem" "chain.pem" "external.sh"
           "fullchain.pem" "full.pem" "key.der" "key.pem" "account_key.json"
         ]);
         default = [ "fullchain.pem" "key.pem" "account_key.json" ];