diff --git a/components/drivers/include/drivers/serial.h b/components/drivers/include/drivers/serial.h
index c7e99ed472..ae6ad5c1fe 100644
--- a/components/drivers/include/drivers/serial.h
+++ b/components/drivers/include/drivers/serial.h
@@ -122,6 +122,8 @@ struct rt_serial_rx_fifo
     rt_uint8_t *buffer;
 
     rt_uint16_t put_index, get_index;
+
+    rt_bool_t is_full;
 };
 
 struct rt_serial_tx_fifo