diff --git a/lib/servers/baseServer.js b/lib/servers/baseServer.js
deleted file mode 100644
index e22bd2a058..0000000000
--- a/lib/servers/baseServer.js
+++ /dev/null
@@ -1,9 +0,0 @@
-'use strict';
-
-// base class that users should extend if they are making their own
-// server implementation
-module.exports = class BaseServer {
-  constructor(server) {
-    this.server = server;
-  }
-};
diff --git a/lib/servers/sockjsServer.js b/lib/servers/sockjsServer.js
deleted file mode 100644
index 8c67abd4e5..0000000000
--- a/lib/servers/sockjsServer.js
+++ /dev/null
@@ -1,64 +0,0 @@
-'use strict';
-
-/* eslint-disable
-  class-methods-use-this,
-  func-names
-*/
-const sockjs = require('sockjs');
-const BaseServer = require('./BaseServer');
-
-// Workaround for sockjs@~0.3.19
-// sockjs will remove Origin header, however Origin header is required for checking host.
-// See https://github.com/webpack/webpack-dev-server/issues/1604 for more information
-{
-  // eslint-disable-next-line global-require
-  const SockjsSession = require('sockjs/lib/transport').Session;
-  const decorateConnection = SockjsSession.prototype.decorateConnection;
-  SockjsSession.prototype.decorateConnection = function(req) {
-    decorateConnection.call(this, req);
-    const connection = this.connection;
-    if (
-      connection.headers &&
-      !('origin' in connection.headers) &&
-      'origin' in req.headers
-    ) {
-      connection.headers.origin = req.headers.origin;
-    }
-  };
-}
-
-module.exports = class SockJSServer extends BaseServer {
-  // options has: error (function), debug (function), server (http/s server), path (string)
-  constructor(server) {
-    super(server);
-    this.socket = sockjs.createServer({
-      // Use provided up-to-date sockjs-client
-      sockjs_url: '/__webpack_dev_server__/sockjs.bundle.js',
-      // Limit useless logs
-      log: (severity, line) => {
-        if (severity === 'error') {
-          this.server.log.error(line);
-        } else {
-          this.server.log.debug(line);
-        }
-      },
-    });
-
-    this.socket.installHandlers(this.server.listeningApp, {
-      prefix: this.server.sockPath,
-    });
-  }
-
-  send(connection, message) {
-    connection.write(message);
-  }
-
-  close(connection) {
-    connection.close();
-  }
-
-  // f should return the resulting connection
-  onConnection(f) {
-    this.socket.on('connection', f);
-  }
-};