diff --git a/flake.nix b/flake.nix
index d6fe3ed..2dd5344 100644
--- a/flake.nix
+++ b/flake.nix
@@ -42,7 +42,7 @@
             systemd.services.rail = {
               wantedBy = [ "multi-user.target" ];
 
-              serviceConfig = let pkg = self.packages.${pkgs.system}.default;
+              serviceConfig = let pkg = self.defaultPackage.${pkgs.system};
               in {
                 Restart = "on-failure";
                 ExecStart = "${pkg}/bin/tmpmail";