diff --git a/nixos/modules/services/networking/ddclient.nix b/nixos/modules/services/networking/ddclient.nix
index a67f0c5de9ba..18f205b8d99e 100644
--- a/nixos/modules/services/networking/ddclient.nix
+++ b/nixos/modules/services/networking/ddclient.nix
@@ -217,7 +217,7 @@ with lib;
         inherit RuntimeDirectory;
         inherit StateDirectory;
         Type = "oneshot";
-        ExecStartPre = "!${pkgs.writeShellScript "ddclient-prestart" preStart}";
+        ExecStartPre = [ "!${pkgs.writeShellScript "ddclient-prestart" preStart}" ];
         ExecStart = "${lib.getExe cfg.package} -file /run/${RuntimeDirectory}/ddclient.conf";
       };
     };