diff --git a/platformio.ini b/platformio.ini
index 45f4bc6ab..92dd7f86a 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -69,6 +69,9 @@ extra_scripts =
 [env]
 monitor_speed = 115200
 monitor_filters = direct
+; on MacBook default upload speed is 921600, which is too fast for USB. Lower for Mac.
+; see https://docs.platformio.org/en/latest/projectconf/sections/env/options/upload/upload_speed.html
+; upload_speed = 460800
 upload_speed = 921600
 build_type = release
 check_tool = cppcheck, clangtidy