diff --git a/README.md b/README.md
index 8e75cacbae..0d3ff793fd 100644
--- a/README.md
+++ b/README.md
@@ -159,6 +159,7 @@ Options:
   --watch-files-reset                       Clear all items provided in 'watchFiles' configuration. Allows to configure list of globs/directories/files
                                             to watch for file changes.
   --web-socket-server <value>               Allows to set web socket server and options (by default 'ws').
+  --no-web-socket-server                    Negative 'web-socket-server' option.
 
 Global options:
   --color                                   Enable colors on console.
diff --git a/bin/cli-flags.js b/bin/cli-flags.js
index b91f9a9eff..af058c1253 100644
--- a/bin/cli-flags.js
+++ b/bin/cli-flags.js
@@ -298,7 +298,7 @@ module.exports = {
     configs: [
       {
         type: 'enum',
-        values: ['sockjs', 'ws'],
+        values: [false, 'sockjs', 'ws'],
         multiple: false,
         description:
           "Allows to set web socket server and options (by default 'ws').",
diff --git a/lib/Server.js b/lib/Server.js
index 2072b8bd90..bba37b1e80 100644
--- a/lib/Server.js
+++ b/lib/Server.js
@@ -671,11 +671,7 @@ class Server {
   }
 
   createWebSocketServer() {
-    this.webSocketServerImplementation =
-      this.getWebSocketServerImplementation();
-    // eslint-disable-next-line new-cap
-    this.webSocketServer = new this.webSocketServerImplementation(this);
-
+    this.webSocketServer = new (this.getWebSocketServerImplementation())(this);
     this.webSocketServer.implementation.on('connection', (client, request) => {
       const headers =
         // eslint-disable-next-line no-nested-ternary
@@ -1037,8 +1033,14 @@ class Server {
             fs.chmodSync(this.options.ipc, READ_WRITE);
           }
 
-          if (Boolean(this.options.hot) || this.options.liveReload) {
-            this.createWebSocketServer();
+          if (this.options.webSocketServer) {
+            try {
+              this.createWebSocketServer();
+            } catch (webSocketServerError) {
+              fn.call(this.server, webSocketServerError);
+
+              return;
+            }
           }
 
           if (this.options.bonjour) {
diff --git a/lib/options.json b/lib/options.json
index 7111f153eb..b35816ecb9 100644
--- a/lib/options.json
+++ b/lib/options.json
@@ -635,7 +635,7 @@
       "link": "https://webpack.js.org/configuration/dev-server/#devserverwebsocketserver"
     },
     "WebSocketServerEnum": {
-      "enum": ["sockjs", "ws"]
+      "enum": [false, "sockjs", "ws"]
     },
     "WebSocketServerFunction": {
       "instanceof": "Function"
diff --git a/lib/utils/DevServerPlugin.js b/lib/utils/DevServerPlugin.js
index 7d417ef8d9..35ffdfe96c 100644
--- a/lib/utils/DevServerPlugin.js
+++ b/lib/utils/DevServerPlugin.js
@@ -18,6 +18,7 @@ class DevServerPlugin {
     let clientImplementationFound = true;
 
     const isKnownWebSocketServerImplementation =
+      this.options.webSocketServer &&
       typeof this.options.webSocketServer.type === 'string' &&
       (this.options.webSocketServer.type === 'ws' ||
         this.options.webSocketServer.type === 'sockjs');
@@ -29,6 +30,8 @@ class DevServerPlugin {
         clientTransport = this.options.client.webSocketTransport;
       } else if (isKnownWebSocketServerImplementation) {
         clientTransport = this.options.webSocketServer.type;
+      } else {
+        clientTransport = 'ws';
       }
     } else {
       clientTransport = 'ws';
@@ -186,8 +189,10 @@ class DevServerPlugin {
    * @returns {string}
    */
   getClientEntry() {
-    const webSocketURL = this.getWebSocketURL();
     /** @type {string} */
+    const webSocketURL = this.options.webSocketServer
+      ? this.getWebSocketURL()
+      : '';
 
     return `${require.resolve('../../client/index.js')}?${webSocketURL}`;
   }
@@ -243,11 +248,8 @@ class DevServerPlugin {
 
     const additionalEntries = [];
 
-    if (
-      this.options.client &&
-      this.isWebTarget(compiler.options) &&
-      (Boolean(this.options.hot) || this.options.liveReload)
-    ) {
+    // TODO maybe empty empty client
+    if (this.options.client && this.isWebTarget(compiler.options)) {
       const clientEntry = this.getClientEntry();
 
       additionalEntries.push(clientEntry);
diff --git a/lib/utils/normalizeOptions.js b/lib/utils/normalizeOptions.js
index aa46b9c167..1861e50a23 100644
--- a/lib/utils/normalizeOptions.js
+++ b/lib/utils/normalizeOptions.js
@@ -409,6 +409,11 @@ function normalizeOptions(compiler, options, logger, cacheDir) {
       type: defaultWebSocketServerType,
       options: defaultWebSocketServerOptions,
     };
+  } else if (
+    typeof options.webSocketServer === 'boolean' &&
+    !options.webSocketServer
+  ) {
+    options.webSocketServer = false;
   } else if (
     typeof options.webSocketServer === 'string' ||
     typeof options.webSocketServer === 'function'
diff --git a/test/__snapshots__/validate-options.test.js.snap.webpack4 b/test/__snapshots__/validate-options.test.js.snap.webpack4
index 5b3294c6ea..69740b58e3 100644
--- a/test/__snapshots__/validate-options.test.js.snap.webpack4
+++ b/test/__snapshots__/validate-options.test.js.snap.webpack4
@@ -666,43 +666,43 @@ exports[`options validate should throw an error on the "webSocketServer" option
 exports[`options validate should throw an error on the "webSocketServer" option with '{"type":true}' value 1`] = `
 "ValidationError: Invalid options object. Dev Server has been initialized using an options object that does not match the API schema.
  - options.webSocketServer should be one of these:
-   \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
+   false | \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
    -> Allows to set web socket server and options (by default 'ws').
    -> Read more at https://webpack.js.org/configuration/dev-server/#devserverwebsocketserver
    Details:
     * options.webSocketServer.type should be one of these:
-      \\"sockjs\\" | \\"ws\\" | non-empty string | function
+      false | \\"sockjs\\" | \\"ws\\" | non-empty string | function
       Details:
        * options.webSocketServer.type should be one of these:
-         \\"sockjs\\" | \\"ws\\"
+         false | \\"sockjs\\" | \\"ws\\"
        * options.webSocketServer.type should be a non-empty string.
        * options.webSocketServer.type should be an instance of function."
 `;
 
-exports[`options validate should throw an error on the "webSocketServer" option with 'false' value 1`] = `
+exports[`options validate should throw an error on the "webSocketServer" option with 'null' value 1`] = `
 "ValidationError: Invalid options object. Dev Server has been initialized using an options object that does not match the API schema.
  - options.webSocketServer should be one of these:
-   \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
+   false | \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
    -> Allows to set web socket server and options (by default 'ws').
    -> Read more at https://webpack.js.org/configuration/dev-server/#devserverwebsocketserver
    Details:
     * options.webSocketServer should be one of these:
-      \\"sockjs\\" | \\"ws\\"
+      false | \\"sockjs\\" | \\"ws\\"
     * options.webSocketServer should be a non-empty string.
     * options.webSocketServer should be an instance of function.
     * options.webSocketServer should be an object:
       object { type?, options? }"
 `;
 
-exports[`options validate should throw an error on the "webSocketServer" option with 'null' value 1`] = `
+exports[`options validate should throw an error on the "webSocketServer" option with 'true' value 1`] = `
 "ValidationError: Invalid options object. Dev Server has been initialized using an options object that does not match the API schema.
  - options.webSocketServer should be one of these:
-   \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
+   false | \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
    -> Allows to set web socket server and options (by default 'ws').
    -> Read more at https://webpack.js.org/configuration/dev-server/#devserverwebsocketserver
    Details:
     * options.webSocketServer should be one of these:
-      \\"sockjs\\" | \\"ws\\"
+      false | \\"sockjs\\" | \\"ws\\"
     * options.webSocketServer should be a non-empty string.
     * options.webSocketServer should be an instance of function.
     * options.webSocketServer should be an object:
diff --git a/test/__snapshots__/validate-options.test.js.snap.webpack5 b/test/__snapshots__/validate-options.test.js.snap.webpack5
index 5b3294c6ea..69740b58e3 100644
--- a/test/__snapshots__/validate-options.test.js.snap.webpack5
+++ b/test/__snapshots__/validate-options.test.js.snap.webpack5
@@ -666,43 +666,43 @@ exports[`options validate should throw an error on the "webSocketServer" option
 exports[`options validate should throw an error on the "webSocketServer" option with '{"type":true}' value 1`] = `
 "ValidationError: Invalid options object. Dev Server has been initialized using an options object that does not match the API schema.
  - options.webSocketServer should be one of these:
-   \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
+   false | \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
    -> Allows to set web socket server and options (by default 'ws').
    -> Read more at https://webpack.js.org/configuration/dev-server/#devserverwebsocketserver
    Details:
     * options.webSocketServer.type should be one of these:
-      \\"sockjs\\" | \\"ws\\" | non-empty string | function
+      false | \\"sockjs\\" | \\"ws\\" | non-empty string | function
       Details:
        * options.webSocketServer.type should be one of these:
-         \\"sockjs\\" | \\"ws\\"
+         false | \\"sockjs\\" | \\"ws\\"
        * options.webSocketServer.type should be a non-empty string.
        * options.webSocketServer.type should be an instance of function."
 `;
 
-exports[`options validate should throw an error on the "webSocketServer" option with 'false' value 1`] = `
+exports[`options validate should throw an error on the "webSocketServer" option with 'null' value 1`] = `
 "ValidationError: Invalid options object. Dev Server has been initialized using an options object that does not match the API schema.
  - options.webSocketServer should be one of these:
-   \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
+   false | \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
    -> Allows to set web socket server and options (by default 'ws').
    -> Read more at https://webpack.js.org/configuration/dev-server/#devserverwebsocketserver
    Details:
     * options.webSocketServer should be one of these:
-      \\"sockjs\\" | \\"ws\\"
+      false | \\"sockjs\\" | \\"ws\\"
     * options.webSocketServer should be a non-empty string.
     * options.webSocketServer should be an instance of function.
     * options.webSocketServer should be an object:
       object { type?, options? }"
 `;
 
-exports[`options validate should throw an error on the "webSocketServer" option with 'null' value 1`] = `
+exports[`options validate should throw an error on the "webSocketServer" option with 'true' value 1`] = `
 "ValidationError: Invalid options object. Dev Server has been initialized using an options object that does not match the API schema.
  - options.webSocketServer should be one of these:
-   \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
+   false | \\"sockjs\\" | \\"ws\\" | non-empty string | function | object { type?, options? }
    -> Allows to set web socket server and options (by default 'ws').
    -> Read more at https://webpack.js.org/configuration/dev-server/#devserverwebsocketserver
    Details:
     * options.webSocketServer should be one of these:
-      \\"sockjs\\" | \\"ws\\"
+      false | \\"sockjs\\" | \\"ws\\"
     * options.webSocketServer should be a non-empty string.
     * options.webSocketServer should be an instance of function.
     * options.webSocketServer should be an object:
diff --git a/test/cli/__snapshots__/basic.test.js.snap.webpack4 b/test/cli/__snapshots__/basic.test.js.snap.webpack4
index ae483ab8a3..38fc8bc38b 100644
--- a/test/cli/__snapshots__/basic.test.js.snap.webpack4
+++ b/test/cli/__snapshots__/basic.test.js.snap.webpack4
@@ -61,6 +61,7 @@ Options:
   --client-web-socket-url-username <value>  Tells clients connected to devServer to use the provided username to authenticate.
   --client-web-socket-url-password <value>  Tells clients connected to devServer to use the provided password to authenticate.
   --web-socket-server <value>               Allows to set web socket server and options (by default 'ws').
+  --no-web-socket-server                    Negative 'web-socket-server' option.
   --compress                                Enables gzip compression for everything served.
   --no-compress                             Disables gzip compression for everything served.
   --history-api-fallback                    Allows to proxy requests through a specified index page (by default 'index.html'), useful for Single Page Applications that utilise the HTML5 History API.
diff --git a/test/cli/__snapshots__/basic.test.js.snap.webpack5 b/test/cli/__snapshots__/basic.test.js.snap.webpack5
index f06d6a70a4..f6e4b254cb 100644
--- a/test/cli/__snapshots__/basic.test.js.snap.webpack5
+++ b/test/cli/__snapshots__/basic.test.js.snap.webpack5
@@ -104,6 +104,7 @@ Options:
   --watch-files <value...>                  Allows to configure list of globs/directories/files to watch for file changes.
   --watch-files-reset                       Clear all items provided in 'watchFiles' configuration. Allows to configure list of globs/directories/files to watch for file changes.
   --web-socket-server <value>               Allows to set web socket server and options (by default 'ws').
+  --no-web-socket-server                    Negative 'web-socket-server' option.
 
 Global options:
   --color                                   Enable colors on console.
diff --git a/test/e2e/__snapshots__/hot-and-live-reload.test.js.snap.webpack4 b/test/e2e/__snapshots__/hot-and-live-reload.test.js.snap.webpack4
index d81f2b3e33..95ac031672 100644
--- a/test/e2e/__snapshots__/hot-and-live-reload.test.js.snap.webpack4
+++ b/test/e2e/__snapshots__/hot-and-live-reload.test.js.snap.webpack4
@@ -1,14 +1,26 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`hot and live reload should not refresh content when hot and no live reload disabled (default): console messages 1`] = `Array []`;
+exports[`hot and live reload should not refresh content when hot and no live reload disabled (default): console messages 1`] = `
+Array [
+  "[webpack-dev-server] App updated. Recompiling...",
+]
+`;
 
 exports[`hot and live reload should not refresh content when hot and no live reload disabled (default): page errors 1`] = `Array []`;
 
-exports[`hot and live reload should not refresh content when hot and no live reload disabled (sockjs): console messages 1`] = `Array []`;
+exports[`hot and live reload should not refresh content when hot and no live reload disabled (sockjs): console messages 1`] = `
+Array [
+  "[webpack-dev-server] App updated. Recompiling...",
+]
+`;
 
 exports[`hot and live reload should not refresh content when hot and no live reload disabled (sockjs): page errors 1`] = `Array []`;
 
-exports[`hot and live reload should not refresh content when hot and no live reload disabled (ws): console messages 1`] = `Array []`;
+exports[`hot and live reload should not refresh content when hot and no live reload disabled (ws): console messages 1`] = `
+Array [
+  "[webpack-dev-server] App updated. Recompiling...",
+]
+`;
 
 exports[`hot and live reload should not refresh content when hot and no live reload disabled (ws): page errors 1`] = `Array []`;
 
@@ -47,6 +59,17 @@ Array [
 
 exports[`hot and live reload should work and allow to disable live reload using the "webpack-dev-server-live-reload=false" (default): page errors 1`] = `Array []`;
 
+exports[`hot and live reload should work and do nothing when web socket server disabled (default): console messages 1`] = `
+Array [
+  "[HMR] Waiting for update signal from WDS...",
+  "WebSocket connection to 'ws://localhost:8095/ws' failed: Error during WebSocket handshake: Unexpected response code: 404",
+  "[webpack-dev-server] JSHandle@object",
+  "[webpack-dev-server] Disconnected!",
+]
+`;
+
+exports[`hot and live reload should work and do nothing when web socket server disabled (default): page errors 1`] = `Array []`;
+
 exports[`hot and live reload should work and refresh content using hot module replacement (default): console messages 1`] = `
 Array [
   "[HMR] Waiting for update signal from WDS...",
diff --git a/test/e2e/__snapshots__/hot-and-live-reload.test.js.snap.webpack5 b/test/e2e/__snapshots__/hot-and-live-reload.test.js.snap.webpack5
index d81f2b3e33..95ac031672 100644
--- a/test/e2e/__snapshots__/hot-and-live-reload.test.js.snap.webpack5
+++ b/test/e2e/__snapshots__/hot-and-live-reload.test.js.snap.webpack5
@@ -1,14 +1,26 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`hot and live reload should not refresh content when hot and no live reload disabled (default): console messages 1`] = `Array []`;
+exports[`hot and live reload should not refresh content when hot and no live reload disabled (default): console messages 1`] = `
+Array [
+  "[webpack-dev-server] App updated. Recompiling...",
+]
+`;
 
 exports[`hot and live reload should not refresh content when hot and no live reload disabled (default): page errors 1`] = `Array []`;
 
-exports[`hot and live reload should not refresh content when hot and no live reload disabled (sockjs): console messages 1`] = `Array []`;
+exports[`hot and live reload should not refresh content when hot and no live reload disabled (sockjs): console messages 1`] = `
+Array [
+  "[webpack-dev-server] App updated. Recompiling...",
+]
+`;
 
 exports[`hot and live reload should not refresh content when hot and no live reload disabled (sockjs): page errors 1`] = `Array []`;
 
-exports[`hot and live reload should not refresh content when hot and no live reload disabled (ws): console messages 1`] = `Array []`;
+exports[`hot and live reload should not refresh content when hot and no live reload disabled (ws): console messages 1`] = `
+Array [
+  "[webpack-dev-server] App updated. Recompiling...",
+]
+`;
 
 exports[`hot and live reload should not refresh content when hot and no live reload disabled (ws): page errors 1`] = `Array []`;
 
@@ -47,6 +59,17 @@ Array [
 
 exports[`hot and live reload should work and allow to disable live reload using the "webpack-dev-server-live-reload=false" (default): page errors 1`] = `Array []`;
 
+exports[`hot and live reload should work and do nothing when web socket server disabled (default): console messages 1`] = `
+Array [
+  "[HMR] Waiting for update signal from WDS...",
+  "WebSocket connection to 'ws://localhost:8095/ws' failed: Error during WebSocket handshake: Unexpected response code: 404",
+  "[webpack-dev-server] JSHandle@object",
+  "[webpack-dev-server] Disconnected!",
+]
+`;
+
+exports[`hot and live reload should work and do nothing when web socket server disabled (default): page errors 1`] = `Array []`;
+
 exports[`hot and live reload should work and refresh content using hot module replacement (default): console messages 1`] = `
 Array [
   "[HMR] Waiting for update signal from WDS...",
diff --git a/test/e2e/__snapshots__/web-socket-server-and-transport.test.js.snap.webpack4 b/test/e2e/__snapshots__/web-socket-server-and-transport.test.js.snap.webpack4
index 444381b68f..2a34f9a5ed 100644
--- a/test/e2e/__snapshots__/web-socket-server-and-transport.test.js.snap.webpack4
+++ b/test/e2e/__snapshots__/web-socket-server-and-transport.test.js.snap.webpack4
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`web socket server and transport should throw an error on wrong path 1`] = `"When you use custom web socket implementation you must explicitly specify client.webSocketTransport. client.webSocketTransport must be a string denoting a default implementation (e.g. 'sockjs', 'ws') or a full path to a JS file via require.resolve(...) which exports a class "`;
+exports[`web socket server and transport should throw an error on wrong path 1`] = `"webSocketServer (webSocketServer.type) must be a string denoting a default implementation (e.g. 'ws', 'sockjs'), a full path to a JS file which exports a class extending BaseServer (webpack-dev-server/lib/servers/BaseServer.js) via require.resolve(...), or the class itself which extends BaseServer"`;
 
 exports[`web socket server and transport should use "sockjs" transport and "sockjs" web socket server 1`] = `
 Array [
diff --git a/test/e2e/__snapshots__/web-socket-server-and-transport.test.js.snap.webpack5 b/test/e2e/__snapshots__/web-socket-server-and-transport.test.js.snap.webpack5
index 444381b68f..2a34f9a5ed 100644
--- a/test/e2e/__snapshots__/web-socket-server-and-transport.test.js.snap.webpack5
+++ b/test/e2e/__snapshots__/web-socket-server-and-transport.test.js.snap.webpack5
@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`web socket server and transport should throw an error on wrong path 1`] = `"When you use custom web socket implementation you must explicitly specify client.webSocketTransport. client.webSocketTransport must be a string denoting a default implementation (e.g. 'sockjs', 'ws') or a full path to a JS file via require.resolve(...) which exports a class "`;
+exports[`web socket server and transport should throw an error on wrong path 1`] = `"webSocketServer (webSocketServer.type) must be a string denoting a default implementation (e.g. 'ws', 'sockjs'), a full path to a JS file which exports a class extending BaseServer (webpack-dev-server/lib/servers/BaseServer.js) via require.resolve(...), or the class itself which extends BaseServer"`;
 
 exports[`web socket server and transport should use "sockjs" transport and "sockjs" web socket server 1`] = `
 Array [
diff --git a/test/e2e/hot-and-live-reload.test.js b/test/e2e/hot-and-live-reload.test.js
index 613590fc2e..1d3a6681f6 100644
--- a/test/e2e/hot-and-live-reload.test.js
+++ b/test/e2e/hot-and-live-reload.test.js
@@ -28,6 +28,12 @@ describe('hot and live reload', () => {
     {
       title: 'should work and refresh content using hot module replacement',
     },
+    {
+      title: 'should work and do nothing when web socket server disabled',
+      options: {
+        webSocketServer: false,
+      },
+    },
     // Default web socket serve ("ws")
     {
       title:
@@ -45,7 +51,6 @@ describe('hot and live reload', () => {
     },
     {
       title: 'should not refresh content when hot and no live reload disabled',
-      noWebSocketServer: true,
       options: {
         hot: false,
         liveReload: false,
@@ -93,7 +98,6 @@ describe('hot and live reload', () => {
     },
     {
       title: 'should not refresh content when hot and no live reload disabled',
-      noWebSocketServer: true,
       options: {
         webSocketServer: 'ws',
         hot: false,
@@ -150,7 +154,6 @@ describe('hot and live reload', () => {
     },
     {
       title: 'should not refresh content when hot and no live reload disabled',
-      noWebSocketServer: true,
       options: {
         allowedHosts: 'all',
 
@@ -281,10 +284,11 @@ describe('hot and live reload', () => {
 
       const webpackOptions = { ...reloadConfig, ...mode.webpackOptions };
       const compiler = webpack(webpackOptions);
+      const testDevServerOptions = mode.options || {};
       const devServerOptions = {
         host: '0.0.0.0',
         port,
-        ...mode.options,
+        ...testDevServerOptions,
       };
       const server = new Server(devServerOptions, compiler);
 
@@ -315,23 +319,24 @@ describe('hot and live reload', () => {
       });
 
       const hot =
-        mode.options && typeof mode.options.hot !== 'undefined'
-          ? mode.options.hot
+        typeof testDevServerOptions.hot !== 'undefined'
+          ? testDevServerOptions.hot
           : true;
       const liveReload =
-        mode.options && typeof mode.options.liveReload !== 'undefined'
-          ? mode.options.liveReload
+        typeof testDevServerOptions.liveReload !== 'undefined'
+          ? testDevServerOptions.liveReload
           : true;
+      const webSocketServerLaunched =
+        testDevServerOptions.webSocketServer !== false;
 
       await new Promise((resolve) => {
-        const webSocketServer =
-          mode.options && typeof mode.options.webSocketServer !== 'undefined'
-            ? mode.options.webSocketServer
+        const webSocketTransport =
+          typeof testDevServerOptions.webSocketServer !== 'undefined' &&
+          testDevServerOptions.webSocketServer !== false
+            ? testDevServerOptions.webSocketServer
             : 'ws';
 
-        const webSocketServerLaunched = hot || liveReload;
-
-        if (webSocketServer === 'ws') {
+        if (webSocketTransport === 'ws') {
           const ws = new WebSocket(
             `ws://127.0.0.1:${devServerOptions.port}/ws`,
             {
@@ -347,13 +352,13 @@ describe('hot and live reload', () => {
           let errored = false;
 
           ws.on('error', (error) => {
-            if (webSocketServerLaunched) {
+            if (!webSocketServerLaunched && /404/.test(error)) {
               errored = true;
-            } else if (!webSocketServerLaunched && /404/.test(error)) {
+            } else {
               errored = true;
-
-              ws.close();
             }
+
+            ws.close();
           });
 
           ws.on('open', () => {
@@ -371,7 +376,7 @@ describe('hot and live reload', () => {
           });
 
           ws.on('close', () => {
-            if (webSocketServerLaunched && opened && received && !errored) {
+            if (opened && received && !errored) {
               resolve();
             } else if (!webSocketServerLaunched && errored) {
               resolve();
@@ -405,13 +410,9 @@ describe('hot and live reload', () => {
           };
 
           sockjs.onclose = (event) => {
-            if (webSocketServerLaunched && opened && received && !errored) {
+            if (opened && received && !errored) {
               resolve();
-            } else if (
-              !webSocketServerLaunched &&
-              event &&
-              event.reason === 'Cannot connect to server'
-            ) {
+            } else if (event && event.reason === 'Cannot connect to server') {
               resolve();
             }
           };
@@ -485,6 +486,7 @@ describe('hot and live reload', () => {
       }
 
       if (
+        webSocketServerLaunched &&
         allowToHotModuleReplacement &&
         ((hot && liveReload) || (hot && !liveReload))
       ) {
@@ -495,12 +497,12 @@ describe('hot and live reload', () => {
         );
 
         expect(doneHotUpdate).toBe(true);
-      } else if (liveReload && allowToLiveReload) {
+      } else if (webSocketServerLaunched && liveReload && allowToLiveReload) {
         await page.waitForNavigation({
           waitUntil: 'networkidle0',
         });
       } else {
-        if (!mode.noWebSocketServer) {
+        if (webSocketServerLaunched) {
           await new Promise((resolve) => {
             const interval = setInterval(() => {
               if (consoleMessages.includes(INVALID_MESSAGE)) {
diff --git a/test/e2e/web-socket-server-and-transport.test.js b/test/e2e/web-socket-server-and-transport.test.js
index 919e346870..d248b4d773 100644
--- a/test/e2e/web-socket-server-and-transport.test.js
+++ b/test/e2e/web-socket-server-and-transport.test.js
@@ -463,6 +463,8 @@ describe('web socket server and transport', () => {
   });
 
   it('should throw an error on wrong path', async () => {
+    expect.assertions(1);
+
     const compiler = webpack(defaultConfig);
     const devServerOptions = {
       port,
@@ -472,24 +474,27 @@ describe('web socket server and transport', () => {
     };
     const server = new Server(devServerOptions, compiler);
 
-    await expect(
-      async () =>
-        new Promise((resolve, reject) => {
-          server.listen(
-            devServerOptions.port,
-            devServerOptions.host,
-            (error) => {
-              if (error) {
-                reject(error);
-
-                return;
-              }
-
-              resolve();
-            }
-          );
-        })
-    ).rejects.toThrowErrorMatchingSnapshot();
+    try {
+      await new Promise((resolve, reject) => {
+        server.listen(devServerOptions.port, devServerOptions.host, (error) => {
+          if (error) {
+            reject(error);
+
+            return;
+          }
+
+          resolve();
+        });
+      });
+    } catch (error) {
+      expect(error.message).toMatchSnapshot();
+    }
+
+    await new Promise((resolve) => {
+      server.close(() => {
+        resolve();
+      });
+    });
   });
 
   it('should use "sockjs" transport, when web socket server is not specify', async () => {
diff --git a/test/validate-options.test.js b/test/validate-options.test.js
index beba527756..27203b8e0f 100644
--- a/test/validate-options.test.js
+++ b/test/validate-options.test.js
@@ -331,6 +331,7 @@ const tests = {
   },
   webSocketServer: {
     success: [
+      false,
       'ws',
       'sockjs',
       {
@@ -352,7 +353,7 @@ const tests = {
     ],
     failure: [
       null,
-      false,
+      true,
       {
         notAnOption: true,
       },