diff --git a/sys/compat/svr4/svr4_ioctl.c b/sys/compat/svr4/svr4_ioctl.c
index 545d20644eed..61f9d75b9143 100644
--- a/sys/compat/svr4/svr4_ioctl.c
+++ b/sys/compat/svr4/svr4_ioctl.c
@@ -119,10 +119,12 @@ svr4_sys_ioctl(td, uap)
 #endif
 
 	switch (cmd & 0xff00) {
+#ifndef BURN_BRIDGES
 	case SVR4_tIOC:
 	        DPRINTF(("ttold\n"));
 		fun = svr4_ttold_ioctl;
 		break;
+#endif
 
 	case SVR4_TIOC:
 	        DPRINTF(("term\n"));
diff --git a/sys/compat/svr4/svr4_ttold.c b/sys/compat/svr4/svr4_ttold.c
index 7672465b7942..3b4b841a789d 100644
--- a/sys/compat/svr4/svr4_ttold.c
+++ b/sys/compat/svr4/svr4_ttold.c
@@ -29,6 +29,8 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#ifndef BURN_BRIDGES
+
 #include <sys/param.h>
 #include <sys/proc.h>
 #include <sys/systm.h>
@@ -376,3 +378,5 @@ svr4_ttold_ioctl(fp, td, retval, fd, cmd, data)
 		return 0;	/* ENOSYS really */
 	}
 }
+
+#endif /* BURN_BRIDGES */
diff --git a/sys/dev/cy/cy.c b/sys/dev/cy/cy.c
index 53e038dad14b..50778d5aeb06 100644
--- a/sys/dev/cy/cy.c
+++ b/sys/dev/cy/cy.c
@@ -1539,9 +1539,11 @@ sioioctl(dev, cmd, data, flag, td)
 	int		mynor;
 	int		s;
 	struct tty	*tp;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	int		oldcmd;
 	struct termios	term;
+#endif
 #endif
 
 	mynor = minor(dev);
@@ -1580,6 +1582,7 @@ sioioctl(dev, cmd, data, flag, td)
 		}
 	}
 	tp = com->tp;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	term = tp->t_termios;
 	oldcmd = cmd;
@@ -1588,6 +1591,7 @@ sioioctl(dev, cmd, data, flag, td)
 		return (error);
 	if (cmd != oldcmd)
 		data = (caddr_t)&term;
+#endif
 #endif
 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
 		int	cc;
diff --git a/sys/dev/digi/digi.c b/sys/dev/digi/digi.c
index 2d9184cda597..19b6cfe1ed21 100644
--- a/sys/dev/digi/digi.c
+++ b/sys/dev/digi/digi.c
@@ -1072,9 +1072,11 @@ digiioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t
 	struct digi_softc *sc;
 	struct digi_p *port;
 	struct tty *tp;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	int oldcmd;
 	struct termios term;
+#endif
 #endif
 
 	mynor = minor(dev);
@@ -1226,6 +1228,7 @@ digiioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t
 	}
 
 	tp = port->tp;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	term = tp->t_termios;
 	oldcmd = cmd;
@@ -1234,6 +1237,7 @@ digiioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *t
 		return (error);
 	if (cmd != oldcmd)
 		data = (caddr_t) & term;
+#endif
 #endif
 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
 		int cc;
diff --git a/sys/dev/rp/rp.c b/sys/dev/rp/rp.c
index 1219ef555f08..6a9eb634bca5 100644
--- a/sys/dev/rp/rp.c
+++ b/sys/dev/rp/rp.c
@@ -1241,9 +1241,11 @@ rpioctl(dev, cmd, data, flag, td)
 	int	error = 0;
 	int	arg, flags, result, ChanStatus;
 	struct	termios *t;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	u_long	oldcmd;
 	struct	termios term;
+#endif
 #endif
 
    umynor = (((minor(dev) >> 16) -1) * 32);    /* SG */
@@ -1289,6 +1291,7 @@ rpioctl(dev, cmd, data, flag, td)
 	tp = rp->rp_tty;
 	cp = &rp->rp_channel;
 
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	term = tp->t_termios;
 	oldcmd = cmd;
@@ -1298,6 +1301,7 @@ rpioctl(dev, cmd, data, flag, td)
 	if(cmd != oldcmd) {
 		data = (caddr_t)&term;
 	}
+#endif
 #endif
 	if((cmd == TIOCSETA) || (cmd == TIOCSETAW) || (cmd == TIOCSETAF)) {
 		int	cc;
diff --git a/sys/dev/si/si.c b/sys/dev/si/si.c
index 97321088cd81..ad7d426054ab 100644
--- a/sys/dev/si/si.c
+++ b/sys/dev/si/si.c
@@ -47,9 +47,11 @@ static const char si_copyright1[] =  "@(#) Copyright (C) Specialix International
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 #include <sys/ioctl_compat.h>
 #endif
+#endif
 #include <sys/tty.h>
 #include <sys/conf.h>
 #include <sys/fcntl.h>
@@ -915,9 +917,11 @@ siioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
 	int mynor = minor(dev);
 	int oldspl;
 	int blocked = 0;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	u_long oldcmd;
 	struct termios term;
+#endif
 #endif
 
 	if (IS_SI_IOCTL(cmd))
@@ -964,6 +968,7 @@ siioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
 	/*
 	 * Do the old-style ioctl compat routines...
 	 */
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	term = tp->t_termios;
 	oldcmd = cmd;
@@ -972,6 +977,7 @@ siioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
 		return (error);
 	if (cmd != oldcmd)
 		data = (caddr_t)&term;
+#endif
 #endif
 	/*
 	 * Do the initial / lock state business
@@ -1008,8 +1014,10 @@ siioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
 	case TIOCSETAW:
 	case TIOCSETAF:
 	case TIOCDRAIN:
+#ifndef BURN_BRIDGES
 #ifdef COMPAT_43
 	case TIOCSETP:
+#endif
 #endif
 		blocked++;	/* block writes for ttywait() and siparam() */
 		si_write_enable(pp, 0);
diff --git a/sys/dev/sio/sio.c b/sys/dev/sio/sio.c
index a71688351355..50a0ccbb0329 100644
--- a/sys/dev/sio/sio.c
+++ b/sys/dev/sio/sio.c
@@ -2065,9 +2065,11 @@ sioioctl(dev, cmd, data, flag, td)
 	int		mynor;
 	int		s;
 	struct tty	*tp;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	u_long		oldcmd;
 	struct termios	term;
+#endif
 #endif
 
 	mynor = minor(dev);
@@ -2075,6 +2077,7 @@ sioioctl(dev, cmd, data, flag, td)
 	if (com == NULL || com->gone)
 		return (ENODEV);
 	tp = com->tp;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	term = tp->t_termios;
 	oldcmd = cmd;
@@ -2083,6 +2086,7 @@ sioioctl(dev, cmd, data, flag, td)
 		return (error);
 	if (cmd != oldcmd)
 		data = (caddr_t)&term;
+#endif
 #endif
 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
 		int	cc;
diff --git a/sys/dev/sx/sx.c b/sys/dev/sx/sx.c
index 0e0687e63f8a..8a523fa378b7 100644
--- a/sys/dev/sx/sx.c
+++ b/sys/dev/sx/sx.c
@@ -35,9 +35,11 @@
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 #include <sys/ioctl_compat.h>
 #endif
+#endif
 #include <sys/tty.h>
 #include <sys/proc.h>
 #include <sys/conf.h>
@@ -703,10 +705,12 @@ sxioctl(
 	int mynor = minor(dev);
 	int oldspl;
 	int blocked = 0;
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	u_long oldcmd;        
 	
 	struct termios term;
+#endif
 #endif
 
 	pp = MINOR2PP(mynor);
@@ -752,6 +756,7 @@ sxioctl(
 	/*
 	 * Do the old-style ioctl compat routines...
 	 */
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	term = tp->t_termios;
 	oldcmd = cmd;
@@ -760,6 +765,7 @@ sxioctl(
 		return(error);
 	if (cmd != oldcmd)
 		data = (caddr_t)&term;
+#endif
 #endif
 	/*
 	 * Do the initial / lock state business
@@ -796,8 +802,10 @@ sxioctl(
 	case TIOCSETAW:
 	case TIOCSETAF:
 	case TIOCDRAIN:
+#ifndef BURN_BRIDGES
 #ifdef COMPAT_43
 	case TIOCSETP:
+#endif
 #endif
 		blocked++;	/* block writes for ttywait() and sxparam() */
 		sx_write_enable(pp, 0);
diff --git a/sys/i386/ibcs2/ibcs2_ioctl.c b/sys/i386/ibcs2/ibcs2_ioctl.c
index 0f80f6f087ce..434da5062fe8 100644
--- a/sys/i386/ibcs2/ibcs2_ioctl.c
+++ b/sys/i386/ibcs2/ibcs2_ioctl.c
@@ -57,6 +57,7 @@ static void stios2stio(struct ibcs2_termios *, struct ibcs2_termio *);
 static void stio2stios(struct ibcs2_termio *, struct ibcs2_termios *);
 
 
+#ifndef BURN_BRIDGES
 int
 ibcs2_gtty(struct thread *td, struct ibcs2_gtty_args *args)
 {
@@ -80,6 +81,7 @@ ibcs2_stty(struct thread *td, struct ibcs2_stty_args *args)
 
 	return ioctl(td, &ioctl_arg);
 }
+#endif /* BURN BRIDGES */
 
 
 /*
diff --git a/sys/i386/ibcs2/ibcs2_sysent.c b/sys/i386/ibcs2/ibcs2_sysent.c
index 7940d3cc1467..4d46451d06fe 100644
--- a/sys/i386/ibcs2/ibcs2_sysent.c
+++ b/sys/i386/ibcs2/ibcs2_sysent.c
@@ -48,8 +48,13 @@ struct sysent ibcs2_sysent[] = {
 	{ AS(ibcs2_fstat_args), (sy_call_t *)ibcs2_fstat },	/* 28 = ibcs2_fstat */
 	{ SYF_MPSAFE | 0, (sy_call_t *)ibcs2_pause },	/* 29 = ibcs2_pause */
 	{ AS(ibcs2_utime_args), (sy_call_t *)ibcs2_utime },	/* 30 = ibcs2_utime */
+#ifndef BURN_BRIDGES
 	{ AS(ibcs2_stty_args), (sy_call_t *)ibcs2_stty },	/* 31 = ibcs2_stty */
 	{ AS(ibcs2_gtty_args), (sy_call_t *)ibcs2_gtty },	/* 32 = ibcs2_gtty */
+#else
+	{ AS(ibcs2_stty_args), (sy_call_t *)nosys },		/* 31 = ibcs2_stty */
+	{ AS(ibcs2_gtty_args), (sy_call_t *)nosys },		/* 32 = ibcs2_gtty */
+#endif
 	{ AS(ibcs2_access_args), (sy_call_t *)ibcs2_access },	/* 33 = ibcs2_access */
 	{ SYF_MPSAFE | AS(ibcs2_nice_args), (sy_call_t *)ibcs2_nice },	/* 34 = ibcs2_nice */
 	{ AS(ibcs2_statfs_args), (sy_call_t *)ibcs2_statfs },	/* 35 = ibcs2_statfs */
diff --git a/sys/kern/tty.c b/sys/kern/tty.c
index 6c5f4d5714d5..bb35a78f1178 100644
--- a/sys/kern/tty.c
+++ b/sys/kern/tty.c
@@ -83,9 +83,11 @@ __FBSDID("$FreeBSD$");
 #include <sys/mutex.h>
 #include <sys/namei.h>
 #include <sys/sx.h>
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 #include <sys/ioctl_compat.h>
 #endif
+#endif
 #include <sys/proc.h>
 #define	TTYDEFCHARS
 #include <sys/tty.h>
@@ -769,6 +771,7 @@ ttioctl(struct tty *tp, u_long cmd, void *data, int flag)
 	case  TIOCSTI:
 	case  TIOCSTOP:
 	case  TIOCSWINSZ:
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 	case  TIOCLBIC:
 	case  TIOCLBIS:
@@ -778,6 +781,7 @@ ttioctl(struct tty *tp, u_long cmd, void *data, int flag)
 	case  TIOCSETN:
 	case  TIOCSETP:
 	case  TIOCSLTC:
+#endif
 #endif
 		sx_slock(&proctree_lock);
 		PROC_LOCK(p);
@@ -1131,7 +1135,11 @@ ttioctl(struct tty *tp, u_long cmd, void *data, int flag)
 		break;
 	default:
 #if defined(COMPAT_43)
+#ifndef BURN_BRIDGES
 		return (ttcompat(tp, cmd, data, flag));
+#else
+		return (ENOIOCTL);
+#endif
 #else
 		return (ENOIOCTL);
 #endif
diff --git a/sys/kern/tty_compat.c b/sys/kern/tty_compat.c
index a7e83fbf21f1..f8975b6e8aca 100644
--- a/sys/kern/tty_compat.c
+++ b/sys/kern/tty_compat.c
@@ -34,6 +34,7 @@ __FBSDID("$FreeBSD$");
 
 #include "opt_compat.h"
 
+#ifndef BURN_BRIDGES
 /*
  * mapping routines for old line discipline (yuck)
  */
@@ -471,3 +472,5 @@ ttcompatsetlflags(struct tty *tp, struct termios *t)
 	t->c_cflag = cflag;
 }
 #endif	/* COMPAT_43 */
+
+#endif /* BURN_BRIDGES */
diff --git a/sys/kern/tty_pty.c b/sys/kern/tty_pty.c
index 1e5d20228a52..1cdea9376a05 100644
--- a/sys/kern/tty_pty.c
+++ b/sys/kern/tty_pty.c
@@ -43,9 +43,11 @@ __FBSDID("$FreeBSD$");
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/sx.h>
+#ifndef BURN_BRIDGES
 #if defined(COMPAT_43)
 #include <sys/ioctl_compat.h>
 #endif
+#endif
 #include <sys/proc.h>
 #include <sys/tty.h>
 #include <sys/conf.h>
@@ -659,9 +661,11 @@ ptyioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td
 			return (EAGAIN);
 
 		switch (cmd) {
+#ifndef BURN_BRIDGES
 #ifdef COMPAT_43
 		case TIOCSETP:
 		case TIOCSETN:
+#endif
 #endif
 		case TIOCSETD:
 		case TIOCSETA:
@@ -734,16 +738,16 @@ ptyioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td
 		case TIOCSETA:
 		case TIOCSETAW:
 		case TIOCSETAF:
+#ifndef BURN_BRIDGES
 #ifdef COMPAT_43
 		case TIOCSETP:
 		case TIOCSETN:
-#endif
-#if defined(COMPAT_43)
 		case TIOCSETC:
 		case TIOCSLTC:
 		case TIOCLBIS:
 		case TIOCLBIC:
 		case TIOCLSET:
+#endif
 #endif
 			pt->pt_send |= TIOCPKT_IOCTL;
 			ptcwakeup(tp, FREAD);
diff --git a/sys/sys/ioctl_compat.h b/sys/sys/ioctl_compat.h
index 98db895e275b..a290a1ad5daf 100644
--- a/sys/sys/ioctl_compat.h
+++ b/sys/sys/ioctl_compat.h
@@ -38,6 +38,7 @@
 #ifndef _SYS_IOCTL_COMPAT_H_
 #define	_SYS_IOCTL_COMPAT_H_
 
+#ifndef BURN_BRIDGES
 #include <sys/ttychars.h>
 #include <sys/ttydev.h>
 
@@ -161,4 +162,5 @@ struct sgttyb {
 #define	NETLDISC	1
 #define	NTTYDISC	2
 
+#endif /* BURN_BRIDGES */
 #endif /* !_SYS_IOCTL_COMPAT_H_ */
diff --git a/sys/sys/ttychars.h b/sys/sys/ttychars.h
index ec9c247a2fa1..67d69e55c4a7 100644
--- a/sys/sys/ttychars.h
+++ b/sys/sys/ttychars.h
@@ -33,6 +33,8 @@
 #ifndef _SYS_TTYCHARS_H_
 #define _SYS_TTYCHARS_H_
 
+#ifndef BURN_BRIDGES
+
 /*
  * 4.3 COMPATIBILITY FILE
  *
@@ -58,4 +60,7 @@ struct ttychars {
 #ifdef USE_OLD_TTY
 #include <sys/ttydefaults.h>	/* to pick up character defaults */
 #endif
+
+#endif /* BURN_BRIDGES */
+
 #endif /* !_SYS_TTYCHARS_H_ */
diff --git a/sys/sys/ttydev.h b/sys/sys/ttydev.h
index d6d6b4c41dc6..f6e3791b4491 100644
--- a/sys/sys/ttydev.h
+++ b/sys/sys/ttydev.h
@@ -35,6 +35,8 @@
 #ifndef _SYS_TTYDEV_H_
 #define	_SYS_TTYDEV_H_
 
+#ifndef BURN_BRIDGES
+
 #ifdef USE_OLD_TTY
 #define B0	0
 #define B50	1
@@ -59,4 +61,6 @@
 #define B921600	20
 #endif /* USE_OLD_TTY */
 
+#endif /* BURN_BRIDGES */
+
 #endif /* !_SYS_TTYDEV_H_ */