diff --git a/src/handler/deploii_handler.h b/src/handler/deploii_handler.h
index 24b95da..993a302 100644
--- a/src/handler/deploii_handler.h
+++ b/src/handler/deploii_handler.h
@@ -1,6 +1,7 @@
 #ifndef Deploii_handler_h
 #define Deploii_handler_h
 
+#include "Arduino.h"
 #if defined(ESP32)
 #include <WiFi.h>
 #include <WebSocketsClient.h>