diff --git a/packages/serve/src/startDevServer.ts b/packages/serve/src/startDevServer.ts
index 8cbe238de76..d0b9116b702 100644
--- a/packages/serve/src/startDevServer.ts
+++ b/packages/serve/src/startDevServer.ts
@@ -11,21 +11,25 @@ import Server from 'webpack-dev-server/lib/Server';
  */
 export default function startDevServer(compiler, options): void {
     const firstWpOpt = compiler.compilers ? compiler.compilers[0].options : compiler.options;
-    const devServerOptions = firstWpOpt.devServer || {};
+    let devServerOptions = firstWpOpt.devServer || {};
+
+    // set default host and port
+    devServerOptions = { host: 'localhost', port: 8080, ...devServerOptions };
 
-    const host = options.host || devServerOptions.host || 'localhost';
-    const port = options.port || devServerOptions.port || 8080;
     // socket should not have a default value, because it should only be used if the
     // user explicitly provides it
     const socket = options.socket || devServerOptions.socket;
 
-    options.host = host;
-    options.port = port;
     if (socket) {
         options.socket = socket;
     }
 
-    const server = new Server(compiler, options);
+    // Compose config from the CLI and devServer object from webpack config
+    const serverConfig = { ...options, ...devServerOptions };
+
+    const { host, port } = serverConfig;
+
+    const server = new Server(compiler, serverConfig);
     server.listen(socket || port, host, (err): void => {
         if (err) {
             throw err;