diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index e1b46bc7e43cd245794f02610afe6c88d49eeb47..0e6866fe0f96d5fb19b0098a85d4a5ba52351d33 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -1161,8 +1161,8 @@ void disassociate_ctty(int on_exit)
 	tty = get_current_tty();
 	if (tty) {
 		tty_pgrp = get_pid(tty->pgrp);
-		mutex_unlock(&tty_mutex);
 		lock_kernel();
+		mutex_unlock(&tty_mutex);
 		/* XXX: here we race, there is nothing protecting tty */
 		if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY)
 			tty_vhangup(tty);