diff --git a/modules/nixos/mail-server/mobileconfig.nix b/modules/nixos/mail-server/mobileconfig.nix
index 5a1c756..f14b37f 100644
--- a/modules/nixos/mail-server/mobileconfig.nix
+++ b/modules/nixos/mail-server/mobileconfig.nix
@@ -60,12 +60,14 @@ lib.mkIf hasMailDiscoveryConfig (
       wantedBy = [ "multi-user.target" ];
       serviceConfig = {
         DynamicUser = true;
-        ExecStart = "${pkgs.python3}/bin/python3 \
-            ${generatorScript} \
-            --domain ${domain} \
-            --mail-host ${cfg.fqdn} \
-            --radicale-host ${radicaleHost} \
-            --port ${toString mobileconfigPort}${defaultUsernameArg}${accountArgs}";
+        ExecStart = lib.concatStringsSep " " [
+          "${pkgs.python3}/bin/python3"
+          "${generatorScript}"
+          "--domain" domain
+          "--mail-host" cfg.fqdn
+          "--radicale-host" radicaleHost
+          "--port" (toString mobileconfigPort)
+        ] + defaultUsernameArg + accountArgs;
         NoNewPrivileges = true;
         PrivateTmp = true;
         ProtectHome = true;