diff --git a/Debug-Serial.md b/Debug-Serial.md
index 8f588df..43afd88 100644
--- a/Debug-Serial.md
+++ b/Debug-Serial.md
@@ -38,7 +38,7 @@ DEBUG_SERIAL_ASCII output is:
 The above is done in `main.c`, see [lines 440](https://github.com/EFeru/hoverboard-firmware-hack-FOC/blob/cf7b1d0de1da34612b056c316480f47702a15cbe/Src/main.c#L440) and [line 225](https://github.com/EFeru/hoverboard-firmware-hack-FOC/blob/cf7b1d0de1da34612b056c316480f47702a15cbe/Src/main.c#L225) by using printf statements, wrapped in ```#if defined(DEBUG_SERIAL_USART2) || defined(DEBUG_SERIAL_USART3)```. More printf statements with same wrapping can be added in other places for monitoring purposes.
 
 ## Debug Protocol:
-If enabled with parameter DEBUG_SERIAL_PROTOCOL in [config.h](https://github.com/EmanuelFeru/hoverboard-firmware-hack-FOC/blob/master/Inc/config.h), debug protocol lets you send Ascii commands.<br>
+If enabled with parameter DEBUG_SERIAL_PROTOCOL in [config.h](https://github.com/EmanuelFeru/hoverboard-firmware-hack-FOC/blob/master/Inc/config.h), in combination with DEBUG_SERIAL_USART2 or DEBUG_SERIAL_USART3 for selecting the right cable, debug protocol lets you send Ascii commands.<br>
 
 ### Commands
 |Command|Usage|Description|