{
  self,
  flake-utils,
  nixpkgs,
  ...
}:
(flake-utils.lib.eachDefaultSystem (
  system:
  let
    pkgs = nixpkgs.legacyPackages.${system};
    formatter = self.formatter.${system};
  in
  {
    checks = {
      format = pkgs.runCommand "check-format" {
        buildInputs = [ formatter ];
      } "${formatter}/bin/nixpkgs-fmt --check ${./.} && touch $out";
    };
  }
)).checks