diff --git a/lib/Server.js b/lib/Server.js
index 136f0a8d66..2a69d75c8e 100644
--- a/lib/Server.js
+++ b/lib/Server.js
@@ -27,6 +27,7 @@ const normalizeOptions = require('./utils/normalizeOptions');
 const updateCompiler = require('./utils/updateCompiler');
 const createLogger = require('./utils/createLogger');
 const getCertificate = require('./utils/getCertificate');
+const checkUrl = require('./utils/checkUrl');
 const status = require('./utils/status');
 const createDomain = require('./utils/createDomain');
 const runBonjour = require('./utils/runBonjour');
@@ -338,7 +339,7 @@ class Server {
       contentBase.forEach((item) => {
         this.app.get('*', express.static(item));
       });
-    } else if (/^(https?:)?\/\//.test(contentBase)) {
+    } else if (checkUrl(contentBase)) {
       this.log.warn(
         'Using a URL as contentBase is deprecated and will be removed in the next major version. Please use the proxy option instead.'
       );
@@ -389,10 +390,7 @@ class Server {
       contentBase.forEach((item) => {
         this.app.get('*', serveIndex(item));
       });
-    } else if (
-      typeof contentBase !== 'number' &&
-      !/^(https?:)?\/\//.test(contentBase)
-    ) {
+    } else if (typeof contentBase !== 'number' && !checkUrl(contentBase)) {
       this.app.get('*', serveIndex(contentBase));
     }
   }
@@ -400,14 +398,11 @@ class Server {
   setupWatchStaticFeature() {
     const contentBase = this.options.contentBase;
 
-    if (
-      /^(https?:)?\/\//.test(contentBase) ||
-      typeof contentBase === 'number'
-    ) {
+    if (checkUrl(contentBase) || typeof contentBase === 'number') {
       throw new Error('Watching remote files is not supported.');
     } else if (Array.isArray(contentBase)) {
       contentBase.forEach((item) => {
-        if (/^(https?:)?\/\//.test(item) || typeof item === 'number') {
+        if (checkUrl(item) || typeof item === 'number') {
           throw new Error('Watching remote files is not supported.');
         }
         this._watch(item);
diff --git a/lib/utils/checkUrl.js b/lib/utils/checkUrl.js
new file mode 100644
index 0000000000..e600bb8f0f
--- /dev/null
+++ b/lib/utils/checkUrl.js
@@ -0,0 +1,7 @@
+'use strict';
+
+function checkUrl(url) {
+  return /^(https?:)?\/\//.test(url);
+}
+
+module.exports = checkUrl;
diff --git a/lib/utils/createConfig.js b/lib/utils/createConfig.js
index 242acbf5bc..bab5a37914 100644
--- a/lib/utils/createConfig.js
+++ b/lib/utils/createConfig.js
@@ -2,6 +2,7 @@
 
 const path = require('path');
 const defaultTo = require('./defaultTo');
+const checkUrl = require('./checkUrl');
 
 function createConfig(config, argv, { port }) {
   const firstWpOpt = Array.isArray(config) ? config[0] : config;
@@ -63,10 +64,7 @@ function createConfig(config, argv, { port }) {
     options.publicPath =
       (firstWpOpt.output && firstWpOpt.output.publicPath) || '';
 
-    if (
-      !/^(https?:)?\/\//.test(options.publicPath) &&
-      options.publicPath[0] !== '/'
-    ) {
+    if (!checkUrl(options.publicPath) && options.publicPath[0] !== '/') {
       options.publicPath = `/${options.publicPath}`;
     }
   }
@@ -113,7 +111,7 @@ function createConfig(config, argv, { port }) {
       options.contentBase = options.contentBase.map((p) => path.resolve(p));
     } else if (/^[0-9]$/.test(options.contentBase)) {
       options.contentBase = +options.contentBase;
-    } else if (!/^(https?:)?\/\//.test(options.contentBase)) {
+    } else if (!checkUrl(options.contentBase)) {
       options.contentBase = path.resolve(options.contentBase);
     }
   }
diff --git a/lib/utils/runOpen.js b/lib/utils/runOpen.js
index 97b73b24b4..d625e4ee51 100644
--- a/lib/utils/runOpen.js
+++ b/lib/utils/runOpen.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const open = require('opn');
+const checkUrl = require('./checkUrl');
 
 function runOpen(uri, options, log) {
   // https://github.com/webpack/webpack-dev-server/issues/1990
@@ -13,7 +14,7 @@ function runOpen(uri, options, log) {
   }
 
   const pageUrl =
-    options.openPage && /^(https?:)?\/\//.test(options.openPage)
+    options.openPage && checkUrl(options.openPage)
       ? options.openPage
       : `${uri}${options.openPage || ''}`;
 
diff --git a/package.json b/package.json
index ec620d5f74..102d09b997 100644
--- a/package.json
+++ b/package.json
@@ -49,7 +49,6 @@
     "import-local": "^2.0.0",
     "internal-ip": "^4.3.0",
     "ip": "^1.1.5",
-    "is-absolute-url": "^3.0.0",
     "killable": "^1.0.1",
     "loglevel": "^1.6.3",
     "opn": "^5.5.0",