diff --git a/firmware/esp32/xterra-controller/bms.h b/firmware/esp32/xterra-controller/bms.h
index c510f32..42f318e 100644
--- a/firmware/esp32/xterra-controller/bms.h
+++ b/firmware/esp32/xterra-controller/bms.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <Arduino.h>
+
 #define BMS_MAX_CELLS 8
 #define MAX_BLE_SCAN_RESULTS 10