diff --git a/lib/util/addDevServerEntrypoints.js b/lib/util/addDevServerEntrypoints.js
index d3d95b3a32..8007049008 100644
--- a/lib/util/addDevServerEntrypoints.js
+++ b/lib/util/addDevServerEntrypoints.js
@@ -27,7 +27,7 @@ module.exports = function addDevServerEntrypoints(webpackOptions, devServerOptio
       } else if (typeof wpOpt.entry === 'function') {
         wpOpt.entry = wpOpt.entry(devClient);
       } else {
-        wpOpt.entry = devClient.concat(wpOpt.entry);
+        wpOpt.entry = devClient.concat(wpOpt.entry || './src');
       }
     });
   }
diff --git a/test/Entry.test.js b/test/Entry.test.js
new file mode 100644
index 0000000000..1ccb2ae6e9
--- /dev/null
+++ b/test/Entry.test.js
@@ -0,0 +1,18 @@
+'use strict';
+
+const assert = require('assert');
+const addDevServerEntrypoints = require('../lib/util/addDevServerEntrypoints');
+
+describe('Entry', () => {
+  it('default to src if no entry point is given', (done) => {
+    const webpackOptions = {};
+    const devServerOptions = {};
+
+    addDevServerEntrypoints(webpackOptions, devServerOptions);
+
+    assert(webpackOptions.entry.length, 2);
+    assert(webpackOptions.entry[1], './src');
+
+    done();
+  });
+});