diff --git a/common/usart.h b/common/usart.h
index 1f37429c8..1b3c6ded7 100644
--- a/common/usart.h
+++ b/common/usart.h
@@ -12,7 +12,7 @@
 void usart_init(void);
 void usart_close(void);
 
-int16_t usart_writebuffer(uint8_t *data, size_t len);
+int16_t usart_writebuffer_sync(uint8_t *data, size_t len);
 uint32_t usart_read_ng(uint8_t *data, size_t len);
 uint16_t usart_rxdata_available(void);
 #define USART_BUFFLEN 512