diff --git a/README.md b/README.md
index 82c6f41..973a41c 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,8 @@ Select Tools -> Upload Method -> STM32CubeProgrammer(SWD)
 
 #### DFU
 Arduino IDE:  
-Select Tools -> Upload Method -> DFU  
+Select Tools -> Upload Method -> DFU
+Select Tools -> Serial Interface -> USB + HW Serial
 
 To put the board in DFU mode, hold down the boot button while pressing and releasing the reset button.
 
@@ -60,4 +61,4 @@ To put the board in DFU mode, hold down the boot button while pressing and relea
 Arduino IDE:  
 Select Tools -> Upload Method -> STLink
 
-Requires an ST-Link debugger connected to SWCLK, SWDIO, Vref, and GND, refer to pin mapping diagram. 
\ No newline at end of file
+Requires an ST-Link debugger connected to SWCLK, SWDIO, Vref, and GND, refer to pin mapping diagram.