diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 594a3c19882b1d2b7af33092111b26b35dfe9b2f..290769c67a8d2e9a611805796996a3cf5d281bbe 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -297,6 +297,7 @@ static ssize_t chars_in_buffer(struct tty_struct *tty)
 
 static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
 {
+	WARN_ONCE(1, "%s is deprecated and scheduled for removal.", __func__);
 	return chars_in_buffer(tty);
 }