diff --git a/src/platforms/stm32/usbuart.c b/src/platforms/stm32/usbuart.c
index 95371dd..f8f56bf 100644
--- a/src/platforms/stm32/usbuart.c
+++ b/src/platforms/stm32/usbuart.c
@@ -138,7 +138,12 @@ static void usbuart_run(void)
 void usbuart_set_line_coding(struct usb_cdc_line_coding *coding)
 {
 	usart_set_baudrate(USBUSART, coding->dwDTERate);
-	usart_set_databits(USBUSART, coding->bDataBits);
+
+	if (coding->bParityType)
+		usart_set_databits(USBUSART, coding->bDataBits + 1);
+	else
+		usart_set_databits(USBUSART, coding->bDataBits);
+
 	switch(coding->bCharFormat) {
 	case 0:
 		usart_set_stopbits(USBUSART, USART_STOPBITS_1);
@@ -150,6 +155,7 @@ void usbuart_set_line_coding(struct usb_cdc_line_coding *coding)
 		usart_set_stopbits(USBUSART, USART_STOPBITS_2);
 		break;
 	}
+
 	switch(coding->bParityType) {
 	case 0:
 		usart_set_parity(USBUSART, USART_PARITY_NONE);