diff --git a/cores/arduino/stm32/usb/cdc/usbd_cdc.c b/cores/arduino/stm32/usb/cdc/usbd_cdc.c
index 5a23bff2e5..c65a654fe0 100644
--- a/cores/arduino/stm32/usb/cdc/usbd_cdc.c
+++ b/cores/arduino/stm32/usb/cdc/usbd_cdc.c
@@ -190,7 +190,7 @@ __ALIGN_BEGIN uint8_t USBD_CDC_CfgHSDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIGN_END =
   0x01,   /* bNumEndpoints: One endpoints used */
   0x02,   /* bInterfaceClass: Communication Interface Class */
   0x02,   /* bInterfaceSubClass: Abstract Control Model */
-  0x01,   /* bInterfaceProtocol: Common AT commands */
+  0x00,   /* bInterfaceProtocol: No specific protocol */
   0x00,   /* iInterface: */
 
   /*Header Functional Descriptor*/
@@ -285,7 +285,7 @@ __ALIGN_BEGIN uint8_t USBD_CDC_CfgFSDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIGN_END =
   0x01,   /* bNumEndpoints: One endpoints used */
   0x02,   /* bInterfaceClass: Communication Interface Class */
   0x02,   /* bInterfaceSubClass: Abstract Control Model */
-  0x01,   /* bInterfaceProtocol: Common AT commands */
+  0x00,   /* bInterfaceProtocol: No specific protocol */
   0x00,   /* iInterface: */
 
   /*Header Functional Descriptor*/
@@ -375,7 +375,7 @@ __ALIGN_BEGIN uint8_t USBD_CDC_OtherSpeedCfgDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIG
   0x01,   /* bNumEndpoints: One endpoints used */
   0x02,   /* bInterfaceClass: Communication Interface Class */
   0x02,   /* bInterfaceSubClass: Abstract Control Model */
-  0x01,   /* bInterfaceProtocol: Common AT commands */
+  0x00,   /* bInterfaceProtocol: No specific protocol */
   0x00,   /* iInterface: */
 
   /*Header Functional Descriptor*/