diff --git a/variants/heltec_v4/platformio.ini b/variants/heltec_v4/platformio.ini
index 54d9a8cd..fb6deed2 100644
--- a/variants/heltec_v4/platformio.ini
+++ b/variants/heltec_v4/platformio.ini
@@ -7,6 +7,7 @@ build_flags =
   -I variants/heltec_v4
   -D HELTEC_LORA_V4
   -D USE_SX1262
+  -D ARDUINO_USB_MODE=1 ; ARDUINO_USB_MODE in heltec_v4.json has no effect
   -D ESP32_CPU_FREQ=80
   -D RADIO_CLASS=CustomSX1262
   -D WRAPPER_CLASS=CustomSX1262Wrapper