diff --git a/common/usart.h b/common/usart.h
index 5fa0873c9..ef0691df5 100644
--- a/common/usart.h
+++ b/common/usart.h
@@ -6,10 +6,13 @@
 
 //#define USART_BAUD_RATE 9600
 #define USART_BAUD_RATE 115200
+
+// BT HC-06 physical layer runs at 128kbps
+// so it's possible to gain a little bit by using 230400
+// with some risk to overflow its internal buffers:
 //#define USART_BAUD_RATE 230400
-//#define USART_BAUD_RATE 460800
-//#define USART_BAUD_RATE 921600
-//#define USART_BAUD_RATE 1382400
+
+// Higher baudrates are pointless, only increasing overflow risk
 
 extern uint32_t usart_baudrate;
 #define USART_PARITY 'N'