diff --git a/extra/healthcheck.js b/extra/healthcheck.js
index b547fbcba..c0b33b6ec 100644
--- a/extra/healthcheck.js
+++ b/extra/healthcheck.js
@@ -1,19 +1,19 @@
-var http = require("http");
-var options = {
-  host: "localhost",
-  port: "3001",
-  timeout: 2000,
+let http = require("http");
+let options = {
+    host: "localhost",
+    port: "3001",
+    timeout: 2000,
 };
-var request = http.request(options, (res) => {
-  console.log(`STATUS: ${res.statusCode}`);
-  if (res.statusCode == 200) {
-    process.exit(0);
-  } else {
-    process.exit(1);
-  }
+let request = http.request(options, (res) => {
+    console.log(`STATUS: ${res.statusCode}`);
+    if (res.statusCode == 200) {
+        process.exit(0);
+    } else {
+        process.exit(1);
+    }
 });
 request.on("error", function (err) {
-  console.log("ERROR");
-  process.exit(1);
+    console.log("ERROR");
+    process.exit(1);
 });
 request.end();
diff --git a/extra/mark-as-nightly.js b/extra/mark-as-nightly.js
index 28496511b..0316596bf 100644
--- a/extra/mark-as-nightly.js
+++ b/extra/mark-as-nightly.js
@@ -1,25 +1,9 @@
-/**
- * String.prototype.replaceAll() polyfill
- * https://gomakethings.com/how-to-replace-a-section-of-a-string-with-another-one-with-vanilla-js/
- * @author Chris Ferdinandi
- * @license MIT
- */
-if (!String.prototype.replaceAll) {
-    String.prototype.replaceAll = function(str, newStr){
-
-        // If a regex pattern
-        if (Object.prototype.toString.call(str).toLowerCase() === '[object regexp]') {
-            return this.replace(str, newStr);
-        }
-
-        // If a string
-        return this.replace(new RegExp(str, 'g'), newStr);
-
-    };
-}
-
-const pkg = require('../package.json');
+const pkg = require("../package.json");
 const fs = require("fs");
+const util = require("../src/util");
+
+util.polyfill();
+
 const oldVersion = pkg.version
 const newVersion = oldVersion + "-nightly"
 
@@ -35,6 +19,6 @@ if (newVersion) {
 
     // Process README.md
     if (fs.existsSync("README.md")) {
-        fs.writeFileSync("README.md", fs.readFileSync("README.md", 'utf8').replaceAll(oldVersion, newVersion))
+        fs.writeFileSync("README.md", fs.readFileSync("README.md", "utf8").replaceAll(oldVersion, newVersion))
     }
 }
diff --git a/extra/update-version.js b/extra/update-version.js
index ab020c383..70d545515 100644
--- a/extra/update-version.js
+++ b/extra/update-version.js
@@ -1,26 +1,10 @@
-/**
- * String.prototype.replaceAll() polyfill
- * https://gomakethings.com/how-to-replace-a-section-of-a-string-with-another-one-with-vanilla-js/
- * @author Chris Ferdinandi
- * @license MIT
- */
-if (!String.prototype.replaceAll) {
-    String.prototype.replaceAll = function(str, newStr) {
-
-        // If a regex pattern
-        if (Object.prototype.toString.call(str).toLowerCase() === "[object regexp]") {
-            return this.replace(str, newStr);
-        }
-
-        // If a string
-        return this.replace(new RegExp(str, "g"), newStr);
-
-    };
-}
-
 const pkg = require("../package.json");
 const fs = require("fs");
 const child_process = require("child_process");
+const util = require("../src/util");
+
+util.polyfill();
+
 const oldVersion = pkg.version;
 const newVersion = process.argv[2];
 
diff --git a/src/util.js b/src/util.js
index 8e80cb61a..2b7141ceb 100644
--- a/src/util.js
+++ b/src/util.js
@@ -1,6 +1,6 @@
 "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.debug = exports.ucfirst = exports.sleep = exports.flipStatus = exports.PENDING = exports.UP = exports.DOWN = exports.appName = void 0;
+exports.polyfill = exports.debug = exports.ucfirst = exports.sleep = exports.flipStatus = exports.PENDING = exports.UP = exports.DOWN = exports.appName = void 0;
 exports.appName = "Uptime Kuma";
 exports.DOWN = 0;
 exports.UP = 1;
@@ -33,3 +33,14 @@ function debug(msg) {
     }
 }
 exports.debug = debug;
+function polyfill() {
+    if (!String.prototype.replaceAll) {
+        String.prototype.replaceAll = function (str, newStr) {
+            if (Object.prototype.toString.call(str).toLowerCase() === "[object regexp]") {
+                return this.replace(str, newStr);
+            }
+            return this.replace(new RegExp(str, "g"), newStr);
+        };
+    }
+}
+exports.polyfill = polyfill;
diff --git a/src/util.ts b/src/util.ts
index 033b98f1d..73a960b5f 100644
--- a/src/util.ts
+++ b/src/util.ts
@@ -1,3 +1,4 @@
+// @ts-nocheck
 // Common Util for frontend and backend
 // Backend uses the compiled file util.js
 // Frontend uses util.ts
@@ -42,3 +43,25 @@ export function debug(msg) {
         console.log(msg);
     }
 }
+
+export function polyfill() {
+    /**
+     * String.prototype.replaceAll() polyfill
+     * https://gomakethings.com/how-to-replace-a-section-of-a-string-with-another-one-with-vanilla-js/
+     * @author Chris Ferdinandi
+     * @license MIT
+     */
+    if (!String.prototype.replaceAll) {
+        String.prototype.replaceAll = function(str, newStr) {
+
+            // If a regex pattern
+            if (Object.prototype.toString.call(str).toLowerCase() === "[object regexp]") {
+                return this.replace(str, newStr);
+            }
+
+            // If a string
+            return this.replace(new RegExp(str, "g"), newStr);
+
+        };
+    }
+}
diff --git a/tsconfig.json b/tsconfig.json
index d47fb63eb..eb23619e4 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,8 +1,11 @@
 {
     "compileOnSave": true,
     "compilerOptions": {
-        "target": "ES2018",
+        "target": "es2018",
         "module": "commonjs",
+        "lib": [
+            "es2020"
+        ],
         "removeComments": true,
         "preserveConstEnums": true,
         "sourceMap": false,