diff --git a/karma.conf.cjs b/karma.conf.cjs
index 16ff72e5a1..2852c6faca 100644
--- a/karma.conf.cjs
+++ b/karma.conf.cjs
@@ -1,12 +1,13 @@
 process.env.CHROME_BIN = require("puppeteer").executablePath();
 const webpackConfig = require("./webpack.config.cjs");
+const webpack = require("webpack");
 
 module.exports = function (config) {
   config.set({
     frameworks: ["webpack", "mocha"],
     files: ["src/lib/**/!(node).spec.ts"],
     preprocessors: {
-      "src/lib/**/!(node).spec.ts": ["env", "webpack"],
+      "src/lib/**/!(node).spec.ts": ["webpack"],
     },
     envPreprocessor: ["CI"],
     reporters: ["progress"],
@@ -20,7 +21,12 @@ module.exports = function (config) {
     webpack: {
       mode: "production",
       module: webpackConfig.module,
-      plugins: webpackConfig.plugins,
+      plugins: [
+        new webpack.DefinePlugin({
+          "process.env.CI": process.env.CI || false,
+        }),
+        ...webpackConfig.plugins,
+      ],
       resolve: webpackConfig.resolve,
       stats: { warnings: false },
     },
diff --git a/package-lock.json b/package-lock.json
index a18bf3706d..a141a03f2e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -67,7 +67,6 @@
         "jsdom-global": "^3.0.2",
         "karma": "^6.3.12",
         "karma-chrome-launcher": "^3.1.0",
-        "karma-env-preprocessor": "^0.1.1",
         "karma-mocha": "^2.0.1",
         "karma-webpack": "^5.0.0",
         "lint-staged": "^12.3.4",
@@ -6883,12 +6882,6 @@
         "which": "bin/which"
       }
     },
-    "node_modules/karma-env-preprocessor": {
-      "version": "0.1.1",
-      "resolved": "https://registry.npmjs.org/karma-env-preprocessor/-/karma-env-preprocessor-0.1.1.tgz",
-      "integrity": "sha1-u+jIfVnADtt2BwvTwxtLOdXcfhU=",
-      "dev": true
-    },
     "node_modules/karma-mocha": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/karma-mocha/-/karma-mocha-2.0.1.tgz",
@@ -17155,12 +17148,6 @@
         }
       }
     },
-    "karma-env-preprocessor": {
-      "version": "0.1.1",
-      "resolved": "https://registry.npmjs.org/karma-env-preprocessor/-/karma-env-preprocessor-0.1.1.tgz",
-      "integrity": "sha1-u+jIfVnADtt2BwvTwxtLOdXcfhU=",
-      "dev": true
-    },
     "karma-mocha": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/karma-mocha/-/karma-mocha-2.0.1.tgz",
diff --git a/package.json b/package.json
index 5a03ffe4c1..2024e7446f 100644
--- a/package.json
+++ b/package.json
@@ -123,7 +123,6 @@
     "jsdom-global": "^3.0.2",
     "karma": "^6.3.12",
     "karma-chrome-launcher": "^3.1.0",
-    "karma-env-preprocessor": "^0.1.1",
     "karma-mocha": "^2.0.1",
     "karma-webpack": "^5.0.0",
     "lint-staged": "^12.3.4",
diff --git a/src/lib/discovery/dns.spec.ts b/src/lib/discovery/dns.spec.ts
index a6d2de5aee..2db676f514 100644
--- a/src/lib/discovery/dns.spec.ts
+++ b/src/lib/discovery/dns.spec.ts
@@ -3,13 +3,6 @@ import { expect } from "chai";
 import { DnsClient, DnsNodeDiscovery } from "./dns";
 import testData from "./testdata.json";
 
-declare global {
-  interface Window {
-    __env__?: any;
-  }
-}
-declare let window: Window | undefined;
-
 const mockData = testData.dns;
 
 const host = "nodes.example.org";
@@ -273,7 +266,7 @@ describe("DNS Node Discovery [live data]", function () {
   const maxQuantity = 3;
 
   before(function () {
-    if (process.env.CI || window?.__env__?.CI) {
+    if (process.env.CI) {
       this.skip();
     }
   });
diff --git a/src/lib/discovery/index.spec.ts b/src/lib/discovery/index.spec.ts
index a0ee745f2b..f68126a033 100644
--- a/src/lib/discovery/index.spec.ts
+++ b/src/lib/discovery/index.spec.ts
@@ -3,13 +3,6 @@ import { expect } from "chai";
 import { fleets } from "./predefined";
 import { getPseudoRandomSubset } from "./random_subset";
 
-declare global {
-  interface Window {
-    __env__?: any;
-  }
-}
-declare let window: Window | undefined;
-
 describe("Discovery", () => {
   it("returns all values when wanted number matches available values", function () {
     const values = ["a", "b", "c"];
@@ -44,7 +37,7 @@ describe("Discovery", () => {
 
 describe("Discovery [live data]", function () {
   before(function () {
-    if (process.env.CI || window?.__env__?.CI) {
+    if (process.env.CI) {
       this.skip();
     }
   });
diff --git a/src/lib/waku.spec.ts b/src/lib/waku.spec.ts
index 77e9c21915..e72bb9db66 100644
--- a/src/lib/waku.spec.ts
+++ b/src/lib/waku.spec.ts
@@ -3,13 +3,6 @@ import PeerId from "peer-id";
 
 import { Waku } from "./waku";
 
-declare global {
-  interface Window {
-    __env__?: any;
-  }
-}
-declare let window: Window | undefined;
-
 describe("Waku Dial", function () {
   describe("Bootstrap [live data]", function () {
     let waku: Waku;
@@ -19,7 +12,7 @@ describe("Waku Dial", function () {
     });
 
     before(function () {
-      if (process.env.CI || window?.__env__?.CI) {
+      if (process.env.CI) {
         this.skip();
       }
     });