diff --git a/lib/Server.js b/lib/Server.js
index 5c03d45ae1..efe8c51a80 100644
--- a/lib/Server.js
+++ b/lib/Server.js
@@ -118,7 +118,7 @@ class Server {
     this.setupDevMiddleware();
 
     // set express routes
-    routes(this.app, this.middleware, this.options);
+    routes(this);
 
     // Keep track of websocket proxies for external websocket upgrade.
     this.websocketProxies = [];
diff --git a/lib/utils/routes.js b/lib/utils/routes.js
index c306abbfb8..21460068a9 100644
--- a/lib/utils/routes.js
+++ b/lib/utils/routes.js
@@ -5,7 +5,11 @@ const { join } = require('path');
 
 const clientBasePath = join(__dirname, '..', '..', 'client');
 
-function routes(app, middleware, options) {
+function routes(server) {
+  const app = server.app;
+  const middleware = server.middleware;
+  const options = server.options;
+
   app.get('/__webpack_dev_server__/live.bundle.js', (req, res) => {
     res.setHeader('Content-Type', 'application/javascript');
 
@@ -30,6 +34,11 @@ function routes(app, middleware, options) {
     createReadStream(join(clientBasePath, 'live.html')).pipe(res);
   });
 
+  app.get('/invalidate', (_req, res) => {
+    server.invalidate();
+    res.end();
+  });
+
   app.get('/webpack-dev-server', (req, res) => {
     res.setHeader('Content-Type', 'text/html');
 
diff --git a/test/server/utils/routes.test.js b/test/server/utils/routes.test.js
index acc94eb8eb..afe5dd40a2 100644
--- a/test/server/utils/routes.test.js
+++ b/test/server/utils/routes.test.js
@@ -64,6 +64,10 @@ describe('routes util', () => {
     });
   });
 
+  it('GET request to invalidate endpoint', (done) => {
+    req.get('/invalidate').expect(200, done);
+  });
+
   it('should handles GET request to live html', (done) => {
     req.get('/webpack-dev-server/').then(({ res }) => {
       expect(res.headers['content-type']).toEqual('text/html');