diff --git a/examples/WebSocketClientStomp/WebSocketClientStomp.ino b/examples/WebSocketClientStomp/WebSocketClientStomp.ino
index bb77c44..a0eb011 100644
--- a/examples/WebSocketClientStomp/WebSocketClientStomp.ino
+++ b/examples/WebSocketClientStomp/WebSocketClientStomp.ino
@@ -16,6 +16,7 @@
 // LIBRARIES
 
 #include <Arduino.h>
+#include <Hash.h>
 
 #include <ESP8266WiFi.h>
 #include <WebSocketsClient.h>