diff --git a/.eslintrc b/.eslintrc
deleted file mode 100644
index 85d4784..0000000
--- a/.eslintrc
+++ /dev/null
@@ -1,63 +0,0 @@
-{
-    "env": {
-        "browser": true,
-        "node": true,
-        "es6": true
-    },
-    "parserOptions": {
-        "ecmaVersion": 6,
-        "sourceType": "module"
-    },
-    "extends": [
-        "eslint:recommended"
-    ],
-    "rules": {
-        "dot-notation": "error",
-        "eqeqeq": ["error", "smart"],
-        "indent": ["off", 4],
-        "keyword-spacing": "error",
-        "linebreak-style": ["error", "unix"],
-        "no-caller": "error",
-        "no-catch-shadow": "error",
-        "no-div-regex": "error",
-        "no-extend-native": "error",
-        "no-extra-bind": "error",
-        "no-floating-decimal": "error",
-        "no-implied-eval": "error",
-        "no-invalid-this": "error",
-        "no-iterator": "error",
-        "no-labels": "error",
-        "no-label-var": "error",
-        "no-lone-blocks": "error",
-        "no-loop-func": "error",
-        "no-multi-str": "error",
-        "no-native-reassign": "error",
-        "no-new": "error",
-        "no-new-func": "error",
-        "no-new-wrappers": "error",
-        "no-octal": "error",
-        "no-octal-escape": "error",
-        "no-process-env": "error",
-        "no-proto": "error",
-        "no-return-assign": "off",
-        "no-script-url": "error",
-        "no-self-compare": "error",
-        "no-sequences": "error",
-        "no-shadow": "off",
-        "no-shadow-restricted-names": "error",
-        "no-throw-literal": "error",
-        "no-unneeded-ternary": "error",
-        "no-unused-expressions": "error",
-        "no-unexpected-multiline": "error",
-        "no-unused-vars": "warn",
-        "no-void": "error",
-        "no-warning-comments": "warn",
-        "no-with": "error",
-        "no-use-before-define": ["off", "nofunc"],
-        "semi": ["error", "always"],
-        "semi-spacing": "error",
-        "space-unary-ops": "error",
-        "wrap-regex": "off",
-        "quotes": ["error", "single"]
-    }
-}
\ No newline at end of file
diff --git a/eslint.config.js b/eslint.config.js
new file mode 100644
index 0000000..ee6f5f9
--- /dev/null
+++ b/eslint.config.js
@@ -0,0 +1,120 @@
+import js from '@eslint/js';
+import globals from 'globals';
+
+const common = {
+  rules: {
+    "accessor-pairs": "error",
+    "array-callback-return": "warn",
+    "arrow-spacing": "warn",
+    "block-scoped-var": "error",
+    "block-spacing": ["warn", "always"],
+    "brace-style": ["warn", "1tbs", { "allowSingleLine": true }],
+    "complexity": ["warn", 50],
+    "curly": ["warn", "multi-line"],
+    "default-case-last": "error",
+    "default-param-last": "error",
+    "dot-notation": "error",
+    "eqeqeq": ["error", "smart"],
+    "func-call-spacing": ["warn", "never"],
+    "grouped-accessor-pairs": "error",
+    "indent": ["off", 4],
+    "keyword-spacing": "error",
+    "linebreak-style": ["error", "unix"],
+    "no-await-in-loop": "error",
+    "no-caller": "error",
+    "no-catch-shadow": "error",
+    "no-console": "warn",
+    "no-constructor-return": "error",
+    "no-div-regex": "error",
+    "no-duplicate-imports": "warn",
+    "no-eq-null": "error",
+    "no-eval": "error",
+    "no-extend-native": "error",
+    "no-extra-bind": "error",
+    "no-extra-label": "error",
+    "no-floating-decimal": "error",
+    "no-global-assign": "error",
+    "no-implied-eval": "error",
+    "no-invalid-this": "off",
+    "no-iterator": "error",
+    "no-labels": "error",
+    "no-label-var": "error",
+    "no-lone-blocks": "error",
+    "no-loop-func": "error",
+    "no-loss-of-precision": "error",
+    "no-multi-str": "error",
+    "no-new": "error",
+    "no-new-func": "error",
+    "no-new-wrappers": "error",
+    "no-octal": "error",
+    "no-octal-escape": "error",
+    "no-process-env": "error",
+    "no-promise-executor-return": "error",
+    "no-proto": "error",
+    "no-prototype-builtins": "off",
+    "no-restricted-properties": "error",
+    "no-return-assign": "off",
+    "no-return-await": "error",
+    "no-script-url": "error",
+    "no-self-compare": "error",
+    "no-sequences": "error",
+    "no-shadow": "off",
+    "no-shadow-restricted-names": "error",
+    "no-template-curly-in-string": "warn",
+    "no-throw-literal": "error",
+    "no-trailing-spaces": "warn",
+    "no-undef": "error",
+    "no-undef-init": "warn",
+    "no-unexpected-multiline": "error",
+    "no-unneeded-ternary": "error",
+    "no-unmodified-loop-condition": "error",
+    "no-unreachable": "warn",
+    "no-unreachable-loop": "warn",
+    "no-unused-expressions": "error",
+    "no-unused-vars": ["warn", { "vars": "all", "args": "none", "caughtErrors": "none" }],
+    "no-use-before-define": ["off", "nofunc"],
+    "no-useless-backreference": "warn",
+    "no-useless-call": "warn",
+    "no-useless-computed-key": "warn",
+    "no-useless-concat": "warn",
+    "no-useless-constructor": "off",
+    "no-useless-escape": "off",
+    "no-useless-rename": "warn",
+    "no-void": "error",
+    "no-warning-comments": "warn",
+    "no-whitespace-before-property": "warn",
+    "no-with": "error",
+    "quotes": ["error", "single", { "allowTemplateLiterals": true }],
+    "radix": ["error", "always"],
+    "require-atomic-updates": "error",
+    "require-await": "error",
+    "semi": ["error", "always"],
+    "semi-spacing": "error",
+    "space-unary-ops": "error",
+    "wrap-regex": "off"
+  }
+};
+
+
+export default [
+  js.configs.recommended,
+  common,
+
+  {
+    files: ['src/**'],
+    languageOptions: {
+      globals: {
+        ...globals.browser,
+        Intl: false
+      }
+    }
+  },
+  {
+    files: ['test/**'],
+    languageOptions: {
+      globals: {
+        ...globals.node
+      }
+    }
+  }
+];
diff --git a/package.json b/package.json
index 5b909ae..c10eafb 100644
--- a/package.json
+++ b/package.json
@@ -36,15 +36,16 @@
     "test:node": "c8 node --test test/"
   },
   "devDependencies": {
-    "c8": "^9.0.0",
-    "esbuild": "^0.19.11",
-    "eslint": "^8.56.0",
+    "c8": "^9.1.0",
+    "esbuild": "^0.20.2",
+    "eslint": "^9.1.1",
+    "globals": "^15.0.0",
     "http-server": "^14.1.1",
     "node-localstorage": "^3.0.5",
     "npm-run-all": "^4.1.5",
     "shx": "^0.3.4"
   },
   "engines": {
-    "node": ">=18"
+    "node": ">=18.18"
   }
 }
diff --git a/src/osm-auth.mjs b/src/osm-auth.mjs
index b64f2e1..3adbff0 100644
--- a/src/osm-auth.mjs
+++ b/src/osm-auth.mjs
@@ -237,7 +237,7 @@ export function osmAuth(o) {
     window.authComplete = function (url) {
       var params = utilStringQs(url.split('?')[1]);
       if (params.state !== state) {
-        error = new Error('Invalid state');
+        var error = new Error('Invalid state');
         error.status = 'invalid-state';
         callback(error);
         return;