Notice that flake-utils is in the flakes registry

flake.lock

@@ -1,5 +1,22 @@
 {
   "nodes": {
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "id": "flake-utils",
+        "type": "indirect"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1694499547,
@@ -15,8 +32,8 @@
     },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs",
-        "utils": "utils"
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
       }
     },
     "systems": {
@@ -33,24 +50,6 @@
         "repo": "default",
         "type": "github"
       }
-    },
-    "utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1694529238,
-        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
     }
   },
   "root": "root",

flake.nix

@@ -1,13 +1,12 @@
 {
   description = "AJA video card software";
-  inputs.utils.url = "github:numtide/flake-utils";
 
   outputs = {
     self,
     nixpkgs,
-    utils,
+    flake-utils,
   }: (
-    utils.lib.eachSystem ["x86_64-linux"] (system: let
+    flake-utils.lib.eachSystem ["x86_64-linux"] (system: let
       pkgs = import nixpkgs {
         inherit system;
       };