diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f7d5bc03d80..460130a5658 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -55,6 +55,8 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - uses: actions/setup-node@v1
+      with:
+        node-version: '12'
     - name: Install Packages
       run: npm install
     - name: Test
diff --git a/karma.conf.js b/karma.conf.js
index 974c8972136..05f1a1ceb6e 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -1,5 +1,6 @@
 "use strict";
 const os = require("os");
+const NodePolyfillPlugin = require("node-polyfill-webpack-plugin");
 
 if (os.arch() === "arm64") {
 
@@ -20,12 +21,11 @@ module.exports = function(config) {
          * frameworks to use
          * available frameworks: https://npmjs.org/browse/keyword/karma-adapter
          */
-        frameworks: ["mocha"],
+        frameworks: ["mocha", "webpack"],
 
 
         // list of files / patterns to load in the browser
         files: [
-            "build/eslint.js",
             "tests/lib/linter/linter.js"
         ],
 
@@ -44,6 +44,14 @@ module.exports = function(config) {
         },
         webpack: {
             mode: "none",
+            plugins: [
+                new NodePolyfillPlugin()
+            ],
+            resolve: {
+                alias: {
+                    "../../../lib/linter$": "../../../build/eslint.js"
+                }
+            },
             stats: "errors-only"
         },
         webpackMiddleware: {
diff --git a/package.json b/package.json
index cdf5a4b180e..3a34facf5a3 100644
--- a/package.json
+++ b/package.json
@@ -108,11 +108,11 @@
     "fs-teardown": "^0.1.0",
     "glob": "^7.1.6",
     "jsdoc": "^3.5.5",
-    "karma": "^4.0.1",
+    "karma": "^6.1.1",
     "karma-chrome-launcher": "^3.1.0",
-    "karma-mocha": "^1.3.0",
-    "karma-mocha-reporter": "^2.2.3",
-    "karma-webpack": "^4.0.0-rc.6",
+    "karma-mocha": "^2.0.1",
+    "karma-mocha-reporter": "^2.2.5",
+    "karma-webpack": "^5.0.0",
     "lint-staged": "^10.1.2",
     "load-perf": "^0.2.0",
     "markdownlint": "^0.19.0",
@@ -120,6 +120,7 @@
     "memfs": "^3.0.1",
     "mocha": "^7.1.1",
     "mocha-junit-reporter": "^1.23.0",
+    "node-polyfill-webpack-plugin": "^1.0.3",
     "npm-license": "^0.3.3",
     "nyc": "^15.0.1",
     "proxyquire": "^2.0.1",
@@ -129,8 +130,8 @@
     "shelljs": "^0.8.2",
     "sinon": "^9.0.1",
     "temp": "^0.9.0",
-    "webpack": "^4.35.0",
-    "webpack-cli": "^3.3.5",
+    "webpack": "^5.23.0",
+    "webpack-cli": "^4.5.0",
     "yorkie": "^2.0.0"
   },
   "keywords": [
diff --git a/tests/lib/linter/linter.js b/tests/lib/linter/linter.js
index f999dd3ad9d..976bd765755 100644
--- a/tests/lib/linter/linter.js
+++ b/tests/lib/linter/linter.js
@@ -5,27 +5,6 @@
 
 "use strict";
 
-//------------------------------------------------------------------------------
-// Helper
-//------------------------------------------------------------------------------
-
-/**
- * To make sure this works in both browsers and Node.js
- * @param {string} name Name of the module to require
- * @param {Object} windowName name of the window
- * @returns {Object} Required object
- * @private
- */
-function compatRequire(name, windowName) {
-    if (typeof window === "object") { // eslint-disable-line no-undef
-        return window[windowName || name]; // eslint-disable-line no-undef
-    }
-    if (typeof require === "function") {
-        return require(name);
-    }
-    throw new Error(`Cannot find object '${name}'.`);
-}
-
 //------------------------------------------------------------------------------
 // Requirements
 //------------------------------------------------------------------------------
@@ -35,7 +14,7 @@ const assert = require("chai").assert,
     esprima = require("esprima"),
     testParsers = require("../../fixtures/parsers/linter-test-parsers");
 
-const { Linter } = compatRequire("../../../lib/linter", "eslint");
+const { Linter } = require("../../../lib/linter");
 
 //------------------------------------------------------------------------------
 // Constants
diff --git a/webpack.config.js b/webpack.config.js
index 2b56290b346..b256f442460 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -1,5 +1,7 @@
 "use strict";
+const NodePolyfillPlugin = require("node-polyfill-webpack-plugin");
 
+/** @type {import("webpack").Configuration} */
 module.exports = {
     mode: "none",
     entry: {
@@ -42,6 +44,9 @@ module.exports = {
             }
         ]
     },
+    plugins: [
+        new NodePolyfillPlugin()
+    ],
     resolve: {
         mainFields: ["browser", "main", "module"]
     },