{
  nix = {
    settings = {
      substituters = [
        "https://nixpkgs-unfree.cachix.org"
      ];
      trusted-public-keys = [
        "nixpkgs-unfree.cachix.org-1:hqvoInulhbV4nJ9yJOEr+4wxhDV4xq2d1DK7S6Nj6rs="
      ];
    };
  };
}