diff --git a/sys/arch/i386/i386/apm.c b/sys/arch/i386/i386/apm.c
index 721ae0e3b968..af1e5c2a7e8d 100644
--- a/sys/arch/i386/i386/apm.c
+++ b/sys/arch/i386/i386/apm.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: apm.c,v 1.60 2001/03/24 02:07:54 christos Exp $ */
+/*	$NetBSD: apm.c,v 1.61 2001/07/14 02:02:45 christos Exp $ */
 
 /*-
  * Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
@@ -42,6 +42,7 @@
 #endif
 
 #include "opt_apm.h"
+#include "opt_compat_mach.h"	/* Needed to get the right segment def */
 
 #ifdef APM_NOIDLE
 #error APM_NOIDLE option deprecated; use APM_NO_IDLE instead
@@ -1349,10 +1350,12 @@ apmattach(parent, self, aux)
 	    ISA_HOLE_VADDR(apminfo.apm_code32_seg_base),
 	    apminfo.apm_code32_seg_len - 1,
 	    SDT_MEMERA, SEL_KPL, 1, 0);
+#ifdef GAPM16CODE_SEL
 	setsegment(&gdt[GAPM16CODE_SEL].sd,
 	    ISA_HOLE_VADDR(apminfo.apm_code16_seg_base),
 	    apminfo.apm_code16_seg_len - 1,
 	    SDT_MEMERA, SEL_KPL, 0, 0);
+#endif
 	if (apminfo.apm_data_seg_len == 0) {
 		/*
 		 *if no data area needed, set up the segment
diff --git a/sys/arch/i386/i386/machdep.c b/sys/arch/i386/i386/machdep.c
index 5b226f8cfba9..6023a15d1202 100644
--- a/sys/arch/i386/i386/machdep.c
+++ b/sys/arch/i386/i386/machdep.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: machdep.c,v 1.446 2001/06/19 15:54:48 sommerfeld Exp $	*/
+/*	$NetBSD: machdep.c,v 1.447 2001/07/14 02:02:46 christos Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 2000 The NetBSD Foundation, Inc.
@@ -85,6 +85,7 @@
 #include "opt_cpureset_delay.h"
 #include "opt_compat_svr4.h"
 #include "opt_realmem.h"
+#include "opt_compat_mach.h"	/* need to get the right segment def */
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -2134,6 +2135,9 @@ extern vector *IDTVEC(exceptions)[];
 #ifdef COMPAT_SVR4
 extern vector IDTVEC(svr4_fasttrap);
 #endif /* COMPAT_SVR4 */
+#ifdef COMPAT_MACH
+extern vector IDTVEC(mach_trap);
+#endif
 
 #define	KBTOB(x)	((size_t)(x) * 1024UL)
 
@@ -2604,10 +2608,15 @@ init386(first_avail)
 	setsegment(&gdt[GBIOSDATA_SEL].sd, 0, 0xfffff, SDT_MEMRWA, SEL_KPL, 0,
 	    0);
 #endif
+#ifdef GMACHCALLS_SEL
+	setgate(&gdt[GMACHCALLS_SEL].gd, &IDTVEC(mach_trap), 1,
+	    SDT_SYS386CGT, SEL_UPL);
+#endif
 
 	/* make ldt gates and memory segments */
 	setgate(&ldt[LSYS5CALLS_SEL].gd, &IDTVEC(osyscall), 1,
 	    SDT_SYS386CGT, SEL_UPL);
+
 	ldt[LUCODE_SEL] = gdt[GUCODE_SEL];
 	ldt[LUDATA_SEL] = gdt[GUDATA_SEL];
 	ldt[LSOL26CALLS_SEL] = ldt[LBSDICALLS_SEL] = ldt[LSYS5CALLS_SEL];
diff --git a/sys/arch/i386/include/segments.h b/sys/arch/i386/include/segments.h
index cceabb827a77..67a30cbb46a1 100644
--- a/sys/arch/i386/include/segments.h
+++ b/sys/arch/i386/include/segments.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: segments.h,v 1.31 2001/05/30 12:28:45 mrg Exp $	*/
+/*	$NetBSD: segments.h,v 1.32 2001/07/14 02:02:45 christos Exp $	*/
 
 /*-
  * Copyright (c) 1995, 1997
@@ -222,7 +222,11 @@ void setsegment __P((struct segment_descriptor *, void *, size_t, int, int,
 #define	GUCODE_SEL	4	/* User code descriptor */
 #define	GUDATA_SEL	5	/* User data descriptor */
 #define	GAPM32CODE_SEL	6
+#ifndef COMPAT_MACH
 #define	GAPM16CODE_SEL	7
+#else
+#define	GMACHCALLS_SEL	7	/* Darwin (mach trap) system call gate */
+#endif
 #define	GAPMDATA_SEL	8
 #define	GBIOSCODE_SEL	9
 #define	GBIOSDATA_SEL	10