diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index d9b561d..d99fec4 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -290,7 +290,7 @@
  *	between the two termios structures, or a speed change is needed.
  */
 
-int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
+int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
 {
 	if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
 		return 1;
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 1dd587ba..955cd0c 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -527,7 +527,7 @@
 }
 
 extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
-extern int tty_termios_hw_change(struct ktermios *a, struct ktermios *b);
+extern int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
 extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
 
 extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);