diff --git a/include/HttpPowerMeter.h b/include/HttpPowerMeter.h
index fde68f6b..3b516923 100644
--- a/include/HttpPowerMeter.h
+++ b/include/HttpPowerMeter.h
@@ -2,6 +2,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <Arduino.h>
 
 class HttpPowerMeterClass {
 public: