diff --git a/eslint.config.js b/eslint.config.js
index c9017f6c..22339fce 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -1,12 +1,26 @@
 import jsdoc from "eslint-plugin-jsdoc";
+import eslintjs from "@eslint/js";
+
+const {configs: eslintConfigs} = eslintjs;
 
 export default [
   jsdoc.configs["flat/recommended"],
+  eslintConfigs["recommended"],
   {
+    languageOptions: {
+      // if we ever use more globals than this, pull in the `globals` package
+      globals: {
+        console: false
+      }
+    },
     rules: {
       "jsdoc/require-param-description": "off",
       "jsdoc/require-returns-description": "off",
       "jsdoc/tag-lines": ["error", "any", { startLines: 1 }],
+      "no-unused-vars": ["error", {
+        argsIgnorePattern: "^_",
+        caughtErrorsIgnorePattern: "^_"
+      }]
     },
   },
 ];
diff --git a/lib/chai/core/assertions.js b/lib/chai/core/assertions.js
index f18da8a9..80a1ce7e 100644
--- a/lib/chai/core/assertions.js
+++ b/lib/chai/core/assertions.js
@@ -2024,11 +2024,11 @@ Assertion.addMethod('property', assertProperty);
 
 /**
  *
- * @param {unknown} name
- * @param {unknown} value
- * @param {string} msg
+ * @param {unknown} _name
+ * @param {unknown} _value
+ * @param {string} _msg
  */
-function assertOwnProperty(name, value, msg) {
+function assertOwnProperty(_name, _value, _msg) {
   flag(this, 'own', true);
   assertProperty.apply(this, arguments);
 }
@@ -4052,7 +4052,7 @@ Assertion.addProperty('frozen', function () {
  * @namespace BDD
  * @public
  */
-Assertion.addProperty('finite', function (msg) {
+Assertion.addProperty('finite', function (_msg) {
   var obj = flag(this, 'object');
 
   this.assert(
diff --git a/lib/chai/interface/assert.js b/lib/chai/interface/assert.js
index 8f0fa9bc..07a6767f 100644
--- a/lib/chai/interface/assert.js
+++ b/lib/chai/interface/assert.js
@@ -3164,16 +3164,22 @@ assert.isNotEmpty = function (val, msg) {
  * @param {unknown} as
  * @returns {unknown}
  */
-(function alias(name, as) {
+const aliases = [
+  ['isOk', 'ok'],
+  ['isNotOk', 'notOk'],
+  ['throws', 'throw'],
+  ['throws', 'Throw'],
+  ['isExtensible', 'extensible'],
+  ['isNotExtensible', 'notExtensible'],
+  ['isSealed', 'sealed'],
+  ['isNotSealed', 'notSealed'],
+  ['isFrozen', 'frozen'],
+  ['isNotFrozen', 'notFrozen'],
+  ['isEmpty', 'empty'],
+  ['isNotEmpty', 'notEmpty'],
+  ['isCallable', 'isFunction'],
+  ['isNotCallable', 'isNotFunction']
+];
+for (const [name, as] of aliases) {
   assert[as] = assert[name];
-  return alias;
-})('isOk', 'ok')('isNotOk', 'notOk')('throws', 'throw')('throws', 'Throw')(
-  'isExtensible',
-  'extensible'
-)('isNotExtensible', 'notExtensible')('isSealed', 'sealed')(
-  'isNotSealed',
-  'notSealed'
-)('isFrozen', 'frozen')('isNotFrozen', 'notFrozen')('isEmpty', 'empty')(
-  'isNotEmpty',
-  'notEmpty'
-)('isCallable', 'isFunction')('isNotCallable', 'isNotFunction');
+}
diff --git a/lib/chai/utils/getEnumerableProperties.js b/lib/chai/utils/getEnumerableProperties.js
deleted file mode 100644
index 46960524..00000000
--- a/lib/chai/utils/getEnumerableProperties.js
+++ /dev/null
@@ -1,25 +0,0 @@
-/*!
- * Chai - getEnumerableProperties utility
- * Copyright(c) 2012-2014 Jake Luer <jake@alogicalparadox.com>
- * MIT Licensed
- */
-
-/**
- * ### .getEnumerableProperties(object)
- *
- * This allows the retrieval of enumerable property names of an object,
- * inherited or not.
- *
- * @param {object} object
- * @returns {Array}
- * @namespace Utils
- * @name getEnumerableProperties
- * @public
- */
-module.exports = function getEnumerableProperties(object) {
-  var result = [];
-  for (var name in object) {
-    result.push(name);
-  }
-  return result;
-};
diff --git a/lib/chai/utils/index.js b/lib/chai/utils/index.js
index b9029bba..70d9f4c1 100644
--- a/lib/chai/utils/index.js
+++ b/lib/chai/utils/index.js
@@ -107,6 +107,12 @@ export function isRegExp(obj) {
   return Object.prototype.toString.call(obj) === '[object RegExp]';
 }
 
+/**
+ * Determines if an object is numeric or not
+ *
+ * @param {unknown} obj Object to test
+ * @returns {boolean}
+ */
 export function isNumeric(obj) {
   return ['Number', 'BigInt'].includes(type(obj));
 }
diff --git a/lib/chai/utils/proxify.js b/lib/chai/utils/proxify.js
index 19112f90..4c1cf695 100644
--- a/lib/chai/utils/proxify.js
+++ b/lib/chai/utils/proxify.js
@@ -64,6 +64,8 @@ export function proxify(obj, nonChainableMethodName) {
         var suggestionDistance = 4;
         getProperties(target).forEach(function (prop) {
           if (
+            // we actually mean to check `Object.prototype` here
+            // eslint-disable-next-line no-prototype-builtins
             !Object.prototype.hasOwnProperty(prop) &&
             builtins.indexOf(prop) === -1
           ) {
@@ -128,17 +130,17 @@ function stringDistanceCapped(strA, strB, cap) {
   // `memo` is a two-dimensional array containing distances.
   // memo[i][j] is the distance between strA.slice(0, i) and
   // strB.slice(0, j).
-  for (var i = 0; i <= strA.length; i++) {
+  for (let i = 0; i <= strA.length; i++) {
     memo[i] = Array(strB.length + 1).fill(0);
     memo[i][0] = i;
   }
-  for (var j = 0; j < strB.length; j++) {
+  for (let j = 0; j < strB.length; j++) {
     memo[0][j] = j;
   }
 
-  for (var i = 1; i <= strA.length; i++) {
+  for (let i = 1; i <= strA.length; i++) {
     var ch = strA.charCodeAt(i - 1);
-    for (var j = 1; j <= strB.length; j++) {
+    for (let j = 1; j <= strB.length; j++) {
       if (Math.abs(i - j) >= cap) {
         memo[i][j] = cap;
         continue;
diff --git a/package-lock.json b/package-lock.json
index b38faf0f..f44d3140 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -16,6 +16,7 @@
         "pathval": "^2.0.0"
       },
       "devDependencies": {
+        "@eslint/js": "^9.17.0",
         "@rollup/plugin-commonjs": "^25.0.7",
         "@web/dev-server-rollup": "^0.6.1",
         "@web/test-runner": "^0.18.0",
@@ -549,12 +550,13 @@
       }
     },
     "node_modules/@eslint/js": {
-      "version": "8.56.0",
-      "resolved": "https://registry.npmjs.org/@eslint/js/-/js-8.56.0.tgz",
-      "integrity": "sha512-gMsVel9D7f2HLkBma9VbtzZRehRogVRfbr++f06nL2vnCGCNlzOD+/MUov/F4p8myyAHspEhVobgjpX64q5m6A==",
+      "version": "9.17.0",
+      "resolved": "https://registry.npmjs.org/@eslint/js/-/js-9.17.0.tgz",
+      "integrity": "sha512-Sxc4hqcs1kTu0iID3kcZDW3JHq2a77HO9P8CP6YEA/FpH3Ll8UXE2r/86Rz9YJLKme39S9vU5OWNjC6Xl0Cr3w==",
       "dev": true,
+      "license": "MIT",
       "engines": {
-        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
+        "node": "^18.18.0 || ^20.9.0 || >=21.1.0"
       }
     },
     "node_modules/@humanwhocodes/config-array": {
@@ -2999,6 +3001,16 @@
         "url": "https://opencollective.com/eslint"
       }
     },
+    "node_modules/eslint/node_modules/@eslint/js": {
+      "version": "8.56.0",
+      "resolved": "https://registry.npmjs.org/@eslint/js/-/js-8.56.0.tgz",
+      "integrity": "sha512-gMsVel9D7f2HLkBma9VbtzZRehRogVRfbr++f06nL2vnCGCNlzOD+/MUov/F4p8myyAHspEhVobgjpX64q5m6A==",
+      "dev": true,
+      "license": "MIT",
+      "engines": {
+        "node": "^12.22.0 || ^14.17.0 || >=16.0.0"
+      }
+    },
     "node_modules/eslint/node_modules/ansi-styles": {
       "version": "4.3.0",
       "resolved": "https://registry.npmjs.org/ansi-styles/-/ansi-styles-4.3.0.tgz",
diff --git a/package.json b/package.json
index f1d2c0cf..4af256d8 100644
--- a/package.json
+++ b/package.json
@@ -52,6 +52,7 @@
     "pathval": "^2.0.0"
   },
   "devDependencies": {
+    "@eslint/js": "^9.17.0",
     "@rollup/plugin-commonjs": "^25.0.7",
     "@web/dev-server-rollup": "^0.6.1",
     "@web/test-runner": "^0.18.0",