diff --git a/examples/esp8266/WebSocketClientSocketIO/WebSocketClientSocketIO.ino b/examples/esp8266/WebSocketClientSocketIO/WebSocketClientSocketIO.ino
index 52aef19..343b5f5 100644
--- a/examples/esp8266/WebSocketClientSocketIO/WebSocketClientSocketIO.ino
+++ b/examples/esp8266/WebSocketClientSocketIO/WebSocketClientSocketIO.ino
@@ -13,6 +13,7 @@
 #include <ArduinoJson.h>
 
 #include <WebSocketsClient.h>
+#include <SocketIOclient.h>
 
 #include <Hash.h>