diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index bd2d91546e32..6d4995a5f318 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -583,6 +583,7 @@ void tty_buffer_init(struct tty_port *port)
 /**
  *	tty_buffer_set_limit	-	change the tty buffer memory limit
  *	@port: tty port to change
+ *	@limit: memory limit to set
  *
  *	Change the tty buffer memory limit.
  *	Must be called before the other tty buffer functions are used.