diff --git a/data/simple.htm b/data/simple.htm
index eb16ecb..5fc8622 100644
--- a/data/simple.htm
+++ b/data/simple.htm
@@ -50,6 +50,7 @@
   <!-- request js from the ESP8266 web server -->
   <script src="js/jquery-3.1.1.min.js"></script>
   <script src="js/bootstrap.min.js"></script>
+  <script src="js/r-websocket.min.js"></script>
 
   <script src="js/simple.js"></script>