diff --git a/platformio.ini b/platformio.ini
index c51a38be..45c62843 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -294,6 +294,7 @@ build_flags = -g
   -Wshadow=compatible-local ;; emit warning in case a local variable "shadows" another local one
   -DARDUINO_ARCH_ESP32 -DESP32
   ${esp32_all_variants.build_flags}
+  -DARDUINO_USB_CDC_ON_BOOT=0 ;; this flag is mandatory for "classic ESP32" when building with arduino-esp32 >=2.0.3
   -D WLED_ENABLE_DMX_INPUT
 lib_deps =
   ${esp32_all_variants.lib_deps}