diff --git a/mach/vax4/libbsd4_2/_brk.s b/mach/vax4/libbsd4_2/_brk.s
index 0e11f5fb..74d7dc80 100644
--- a/mach/vax4/libbsd4_2/_brk.s
+++ b/mach/vax4/libbsd4_2/_brk.s
@@ -1,28 +1,25 @@
 #include "syscall.h"
 DEFINE(__brk)
-	cmpl	4(ap),Imin
+	cmpl	4(ap),$endbss
 	bgeq	Iok
-	movl	Imin,4(ap)
+	movl	$endbss,4(ap)
 Iok:
 	chmk	$17
 	bcs	Ierr
-	movl	4(ap),Icur
+	movl	4(ap),.limhp
 	clrl	r0
 	ret
 Ierr:
 	jmp	cerror
 
 DEFINE(__sbrk)
-	addl3	Icur,4(ap),-(sp)
+	addl3	.limhp,4(ap),-(sp)
 	bcs	Ierr
 	pushl	$1
 	movl	ap,r3
 	movl	sp,ap
 	chmk	$17
 	bcs	Ierr
-	movl	Icur,r0
-	addl2	4(r3),Icur
+	movl	.limhp,r0
+	addl2	4(r3),.limhp
 	ret
-.sect .data
-Imin: .data4	endbss
-Icur: .data4	endbss
diff --git a/mach/vax4/libbsd4_2/brk.s b/mach/vax4/libbsd4_2/brk.s
index 3d2f8c4a..c40c2cdd 100644
--- a/mach/vax4/libbsd4_2/brk.s
+++ b/mach/vax4/libbsd4_2/brk.s
@@ -1,29 +1,25 @@
 #include "syscall.h"
-.extern	_end
 DEFINE(_brk)
-	cmpl	4(ap),Imin
+	cmpl	4(ap),$endbss
 	bgeq	Iok
-	movl	Imin,4(ap)
+	movl	$endbss,4(ap)
 Iok:
 	chmk	$17
 	bcs	Ierr
-	movl	4(ap),Icur
+	movl	4(ap),.limhp
 	clrl	r0
 	ret
 Ierr:
 	jmp	cerror
 
 DEFINE(_sbrk)
-	addl3	Icur,4(ap),-(sp)
+	addl3	.limhp,4(ap),-(sp)
 	bcs	Ierr
 	pushl	$1
 	movl	ap,r3
 	movl	sp,ap
 	chmk	$17
 	bcs	Ierr
-	movl	Icur,r0
-	addl2	4(r3),Icur
+	movl	.limhp,r0
+	addl2	4(r3),.limhp
 	ret
-.sect .data
-Imin: .data4	_end
-Icur: .data4	_end
diff --git a/mach/vax4/libbsd4_2/head_em.s b/mach/vax4/libbsd4_2/head_em.s
index b78019a2..59819fda 100644
--- a/mach/vax4/libbsd4_2/head_em.s
+++ b/mach/vax4/libbsd4_2/head_em.s
@@ -6,6 +6,7 @@
 .sect .text
 .define	hol0
 .define	.reghp
+.define	.limhp
 .define	.trppc
 .define	.trpim
 
@@ -84,6 +85,8 @@ Im2:
 	.data4	0
 .reghp:
 	.data4	_end
+.limhp:
+	.data4	_end
 hol0:
 	.space	8
 .trppc: