diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 4c57599f68ab..81874f802499 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -36,7 +36,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)tty.c	8.8 (Berkeley) 1/21/94
- * $Id: tty.c,v 1.65 1995/07/31 22:48:33 bde Exp $
+ * $Id: tty.c,v 1.66 1995/07/31 22:50:01 bde Exp $
  */
 
 /*-
@@ -175,6 +175,12 @@ char const char_type[] = {
 #undef	TB
 #undef	VT
 
+int validspeed[] = {
+	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200,
+	1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200
+};
+#define MAX_SPEED (sizeof(validspeed)/sizeof(*validspeed) - 1)
+
 /* Macros to clear/set/test flags. */
 #define	SET(t, f)	(t) |= (f)
 #define	CLR(t, f)	(t) &= ~(f)
@@ -823,6 +829,18 @@ ttioctl(tp, cmd, data, flag)
 	case TIOCSETAW:			/* drain output, set */
 	case TIOCSETAF: {		/* drn out, fls in, set */
 		register struct termios *t = (struct termios *)data;
+		register int i;
+
+		for (i = MAX_SPEED; i >= 0; i--)
+			if (t->c_ispeed == validspeed[i])
+				break;
+		if (i < 0)
+			return (EINVAL);
+		for (i = MAX_SPEED; i >= 0; i--)
+			if (t->c_ospeed == validspeed[i])
+				break;
+		if (i < 0)
+			return (EINVAL);
 
 		s = spltty();
 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
diff --git a/sys/kern/tty_compat.c b/sys/kern/tty_compat.c
index 9b4b73129bad..628b11c8191c 100644
--- a/sys/kern/tty_compat.c
+++ b/sys/kern/tty_compat.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)tty_compat.c	8.1 (Berkeley) 6/10/93
- * $Id: tty_compat.c,v 1.12 1995/04/11 17:54:25 ache Exp $
+ * $Id: tty_compat.c,v 1.13 1995/05/30 08:06:09 rgrimes Exp $
  */
 
 /*
@@ -78,10 +78,7 @@ static struct speedtab compatspeeds[] = {
 	{ 0,	0 },
 	{ -1,	-1 },
 };
-static int compatspcodes[] = {
-	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200,
-	1800, 2400, 4800, 9600, 19200, 38400, 57600, 115200,
-};
+extern int validspeed[];     /* in tty.c */
 
 int ttsetcompat(tp, com, data, term)
 	register struct tty *tp;
@@ -98,11 +95,11 @@ int ttsetcompat(tp, com, data, term)
 		if ((speed = sg->sg_ispeed) > MAX_SPEED || speed < 0)
 			return(EINVAL);
 		else
-			term->c_ispeed = compatspcodes[speed];
+			term->c_ispeed = validspeed[speed];
 		if ((speed = sg->sg_ospeed) > MAX_SPEED || speed < 0)
 			return(EINVAL);
 		else
-			term->c_ospeed = compatspcodes[speed];
+			term->c_ospeed = validspeed[speed];
 		term->c_cc[VERASE] = sg->sg_erase;
 		term->c_cc[VKILL] = sg->sg_kill;
 		tp->t_flags = (tp->t_flags&0xffff0000) | (sg->sg_flags&0xffff);