diff --git a/drivers/char/ttyprintk.c b/drivers/char/ttyprintk.c
index 6a0059e508e3..ff3b9a41b91b 100644
--- a/drivers/char/ttyprintk.c
+++ b/drivers/char/ttyprintk.c
@@ -158,12 +158,26 @@ static int tpk_ioctl(struct tty_struct *tty,
 	return 0;
 }
 
+/*
+ * TTY operations hangup function.
+ */
+static void tpk_hangup(struct tty_struct *tty)
+{
+	struct ttyprintk_port *tpkp = tty->driver_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tpkp->port.lock, flags);
+	tpkp->port.count = 0;
+	spin_unlock_irqrestore(&tpkp->port.lock, flags);
+}
+
 static const struct tty_operations ttyprintk_ops = {
 	.open = tpk_open,
 	.close = tpk_close,
 	.write = tpk_write,
 	.write_room = tpk_write_room,
 	.ioctl = tpk_ioctl,
+	.hangup = tpk_hangup,
 };
 
 static const struct tty_port_operations null_ops = { };