diff --git a/flake.lock b/flake.lock
index 97f8967..044c1eb 100644
--- a/flake.lock
+++ b/flake.lock
@@ -16,24 +16,6 @@
         "type": "github"
       }
     },
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1710146030,
-        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1715395895,
@@ -53,24 +35,8 @@
     "root": {
       "inputs": {
         "edge-nixpkgs": "edge-nixpkgs",
-        "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs"
       }
-    },
-    "systems": {
-      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
-        "type": "github"
-      }
     }
   },
   "root": "root",
diff --git a/flake.nix b/flake.nix
index 58dc5a7..8029aaa 100644
--- a/flake.nix
+++ b/flake.nix
@@ -7,7 +7,6 @@
     #   - `nix flake update --commit-lock-file` # https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-flake-update.html
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
     edge-nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
-    flake-utils.url = "github:numtide/flake-utils";
   };
 
   outputs =
@@ -15,37 +14,48 @@
       self,
       nixpkgs,
       edge-nixpkgs,
-      flake-utils,
     }:
-    flake-utils.lib.eachDefaultSystem (
-      system:
-      let
-        pkgs = nixpkgs.legacyPackages.${system};
-        edge-pkgs = edge-nixpkgs.legacyPackages.${system};
-      in
-      {
-        # Q. Why nixfmt? Not nixpkgs-fmt and alejandra?
-        # A. nixfmt will be official
-        # - https://github.com/NixOS/nixfmt/issues/153
-        # - https://github.com/NixOS/nixfmt/issues/129
-        # - https://github.com/NixOS/rfcs/pull/166
-        formatter = edge-pkgs.nixfmt-rfc-style;
-        devShells.default =
-          with pkgs;
-          mkShell {
-            buildInputs = [
-              # https://github.com/NixOS/nix/issues/730#issuecomment-162323824
-              # https://github.com/kachick/dotfiles/pull/228
-              bashInteractive
-              findutils # xargs
-              edge-pkgs.nixfmt-rfc-style
-              nil
-              go-task
+    let
+      # Candidates: https://github.com/NixOS/nixpkgs/blob/release-23.11/lib/systems/flake-systems.nix
+      forAllSystems = nixpkgs.lib.genAttrs [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        # I don't have M1+ mac, providing this for macos-14 free runner https://github.com/actions/runner-images/issues/9741
+        "aarch64-darwin"
+      ];
+    in
+    {
+      # Q. Why nixfmt? Not nixpkgs-fmt and alejandra?
+      # A. nixfmt will be official
+      # - https://github.com/NixOS/nixfmt/issues/153
+      # - https://github.com/NixOS/nixfmt/issues/129
+      # - https://github.com/NixOS/rfcs/pull/166
+      formatter = forAllSystems (system: edge-nixpkgs.legacyPackages.${system}.nixfmt-rfc-style);
+      devShells = forAllSystems (
+        system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+          edge-pkgs = edge-nixpkgs.legacyPackages.${system};
+        in
+        {
+          default =
+            with pkgs;
+            mkShell {
+              buildInputs = [
+                # https://github.com/NixOS/nix/issues/730#issuecomment-162323824
+                # https://github.com/kachick/dotfiles/pull/228
+                bashInteractive
+                findutils # xargs
+                edge-pkgs.nixfmt-rfc-style
+                nil
+                go-task
 
-              edge-pkgs.dprint
-              edge-pkgs.typos
-            ];
-          };
-      }
-    );
+                edge-pkgs.dprint
+                edge-pkgs.typos
+              ];
+            };
+        }
+      );
+    };
 }