diff --git a/lib/libc/gmon/gmon.c b/lib/libc/gmon/gmon.c
index eebce0a5cac5..6ca8f79267b6 100644
--- a/lib/libc/gmon/gmon.c
+++ b/lib/libc/gmon/gmon.c
@@ -37,6 +37,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/param.h>
 #include <sys/time.h>
 #include <sys/gmon.h>
+#include <sys/mman.h>
 #include <sys/sysctl.h>
 
 #include <err.h>
@@ -50,14 +51,6 @@ __FBSDID("$FreeBSD$");
 
 #include "libc_private.h"
 
-#if defined(__i386__) || defined(__sparc64__) || defined(__amd64__) || (defined(__powerpc__) && !defined(__powerpc64__))
-extern char *minbrk __asm (".minbrk");
-#elif defined(__powerpc64__)
-extern char *minbrk __asm ("_minbrk");
-#else
-extern char *minbrk __asm ("minbrk");
-#endif
-
 struct gmonparam _gmonparam = { GMON_PROF_OFF };
 
 static int	s_scale;
@@ -94,8 +87,9 @@ monstartup(u_long lowpc, u_long highpc)
 		p->tolimit = MAXARCS;
 	p->tossize = p->tolimit * sizeof(struct tostruct);
 
-	cp = sbrk(p->kcountsize + p->fromssize + p->tossize);
-	if (cp == (char *)-1) {
+	cp = mmap(NULL, p->kcountsize + p->fromssize + p->tossize,
+	    PROT_READ | PROT_WRITE, MAP_ANON, -1, 0);
+	if (cp == MAP_FAILED) {
 		ERR("monstartup: out of memory\n");
 		return;
 	}
@@ -108,7 +102,6 @@ monstartup(u_long lowpc, u_long highpc)
 	cp += p->kcountsize;
 	p->froms = (u_short *)cp;
 
-	minbrk = sbrk(0);
 	p->tos[0].link = 0;
 
 	o = p->highpc - p->lowpc;