{
  description = "nixos-config";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    stable = { url = "github:nixos/nixpkgs/nixos-20.03"; };
    hardware = { url = "github:nixos/nixos-hardware"; };
    home-manager.url = "github:nix-community/home-manager";
    nixpkgs-wayland = { url = "github:colemickens/nixpkgs-wayland"; };
    firefox = { url = "github:colemickens/flake-firefox-nightly"; };
    firefox.inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs = inputs: {
    nixosConfigurations.positron = inputs.nixpkgs.lib.nixosSystem {
      inputs.nixpkgs.pkgs = inputs.nixpkgs.lib.mkForce pkgs;
      modules = [
        ./hosts/positron/configuration.nix
        inputs.hardware.nixosModules.lenovo-thinkpad-x230
      ];
      specialArgs = { inherit inputs; };
      # Select the target system here.
      system = "x86_64-linux";
    };
  };
}