diff --git a/flake.lock b/flake.lock
index 6268b4f..33bc7cd 100644
--- a/flake.lock
+++ b/flake.lock
@@ -33,10 +33,6 @@
     },
     "root": {
       "inputs": {
-        "flake-utils": [
-          "rust-overlay",
-          "flake-utils"
-        ],
         "nixpkgs": [
           "rust-overlay",
           "nixpkgs"
diff --git a/flake.nix b/flake.nix
index ecf61a3..ea42f6a 100644
--- a/flake.nix
+++ b/flake.nix
@@ -3,67 +3,90 @@
 
   inputs = {
     rust-overlay.url = "github:oxalica/rust-overlay";
-    flake-utils.follows = "rust-overlay/flake-utils";
     nixpkgs.follows = "rust-overlay/nixpkgs";
   };
 
-  outputs = inputs@{self, nixpkgs, flake-utils, ...}:
-    flake-utils.lib.eachDefaultSystem (system:
+  outputs =
+    {
+      self,
+      nixpkgs,
+      rust-overlay,
+    }:
     let
-      pkgs = import nixpkgs {
-        inherit system;
-        overlays = [
-          inputs.rust-overlay.overlays.default
-        ];
-      };
+      pkgsFor =
+        system:
+        import nixpkgs {
+          inherit system;
+          overlays = [
+            rust-overlay.overlays.default
+          ];
+        };
+      lib = nixpkgs.lib;
+      eachSupportedSystem = lib.genAttrs lib.systems.flakeExposed;
     in
     {
-      packages.bvg = let
-        env = pkgs.bundlerEnv {
-          name = "bvg-env";
-          ruby = pkgs.ruby;
-          gemfile = bvg/Gemfile;
-          lockfile = bvg/Gemfile.lock;
-          gemset = bvg/gemset.nix;
-        };
-      in pkgs.stdenv.mkDerivation {
-        name = "bvg";
-        buildInput = [env.wrappedRuby];
-        script = bvg/bvg.rb;
-        buildCommand = ''
-          install -D -m755 $script $out/bin/bvg
-          patchShebangs $out/bin/bvg
-        '';
-      };
-      packages.onomap = pkgs.haskellPackages.callCabal2nix "onomap" ./onomastics-ng {};
-      packages.alarm = pkgs.writers.writeDashBin "alarm" ''
-        set -efu
-        export PATH=${nixpkgs.lib.makeBinPath [pkgs.coreutils pkgs.bc self.packages.${system}.rusty-jeep]}
-        for i in `seq 8000 1000 10000`; do
-        echo $i 100
-        done | rusty-jeep
-        echo 'if you heard that sound, then goto sleep..^_^'
+      packages = eachSupportedSystem (
+        system:
+        let
+          pkgs = pkgsFor system;
+        in
+        {
+          bvg =
+            let
+              env = pkgs.bundlerEnv {
+                name = "bvg-env";
+                ruby = pkgs.ruby;
+                gemfile = bvg/Gemfile;
+                lockfile = bvg/Gemfile.lock;
+                gemset = bvg/gemset.nix;
+              };
+            in
+            pkgs.stdenv.mkDerivation {
+              name = "bvg";
+              buildInput = [ env.wrappedRuby ];
+              script = bvg/bvg.rb;
+              buildCommand = ''
+                install -D -m755 $script $out/bin/bvg
+                patchShebangs $out/bin/bvg
+              '';
+            };
+          onomap = pkgs.haskellPackages.callCabal2nix "onomap" ./onomastics-ng { };
+          alarm = pkgs.writers.writeDashBin "alarm" ''
+            set -efu
+            export PATH=${
+              nixpkgs.lib.makeBinPath [
+                pkgs.coreutils
+                pkgs.bc
+                self.packages.${system}.rusty-jeep
+              ]
+            }
+            for i in `seq 8000 1000 10000`; do
+            echo $i 100
+            done | rusty-jeep
+            echo 'if you heard that sound, then goto sleep..^_^'
 
-        echo sleep "$@"
-        sleep "$@"
+            echo sleep "$@"
+            sleep "$@"
 
-        echo 'wake up!'
-        while :; do
-        echo $(echo "($(od -tu -An -N 2 /dev/urandom)%1000)+500"|bc) $(echo "($(od -tu -An -N 2 /dev/urandom)%500)+100"|bc)
-        done | rusty-jeep 1
-      '';
-      packages.rusty-jeep = pkgs.rustPlatform.buildRustPackage rec {
-        name = "rusty-jeep";
-        version = "1.0.0";
-        src = ./rusty-jeep;
-        nativeBuildInputs = [pkgs.pkg-config];
-        buildInputs = [pkgs.alsa-lib];
-        cargoHash = "sha256-L3lpWEb2y9+45jWnpWNBsYU4nNDx0reSxjw1eKYb+6A=";
-        meta = with nixpkgs.lib; {
-          description = "A beeping program inspired by K_belwagen";
-          license = licenses.wtfpl;
-          maintainers = [maintainers.kmein];
-        };
-      };
-    });
+            echo 'wake up!'
+            while :; do
+            echo $(echo "($(od -tu -An -N 2 /dev/urandom)%1000)+500"|bc) $(echo "($(od -tu -An -N 2 /dev/urandom)%500)+100"|bc)
+            done | rusty-jeep 1
+          '';
+          rusty-jeep = pkgs.rustPlatform.buildRustPackage rec {
+            name = "rusty-jeep";
+            version = "1.0.0";
+            src = ./rusty-jeep;
+            nativeBuildInputs = [ pkgs.pkg-config ];
+            buildInputs = [ pkgs.alsa-lib ];
+            cargoHash = "sha256-L3lpWEb2y9+45jWnpWNBsYU4nNDx0reSxjw1eKYb+6A=";
+            meta = with nixpkgs.lib; {
+              description = "A beeping program inspired by K_belwagen";
+              license = licenses.wtfpl;
+              maintainers = [ maintainers.kmein ];
+            };
+          };
+        }
+      );
+    };
 }