diff --git a/sys/dev/dkwedge/dkwedge_bsdlabel.c b/sys/dev/dkwedge/dkwedge_bsdlabel.c
index c05e9a8040fe..aef19cac24a8 100644
--- a/sys/dev/dkwedge/dkwedge_bsdlabel.c
+++ b/sys/dev/dkwedge/dkwedge_bsdlabel.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: dkwedge_bsdlabel.c,v 1.9 2006/11/16 01:32:50 christos Exp $	*/
+/*	$NetBSD: dkwedge_bsdlabel.c,v 1.10 2007/03/01 21:30:50 martin Exp $	*/
 
 /*-
  * Copyright (c) 2004 The NetBSD Foundation, Inc.
@@ -86,7 +86,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dkwedge_bsdlabel.c,v 1.9 2006/11/16 01:32:50 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dkwedge_bsdlabel.c,v 1.10 2007/03/01 21:30:50 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -226,6 +226,7 @@ validate_label(mbr_args_t *a, daddr_t label_sector, size_t label_offset)
 	struct disklabel *lp;
 	caddr_t lp_lim;
 	int i, error;
+	u_int checksum;
 
 	error = dkwedge_read(a->pdk, a->vp, label_sector, a->buf, DEV_BSIZE);
 	if (error) {
@@ -264,6 +265,8 @@ validate_label(mbr_args_t *a, daddr_t label_sector, size_t label_offset)
 					    bswap16(lp->d_npartitions));
 					continue;
 				}
+				checksum = dkcksum_sized(lp,
+				    bswap16(lp->d_npartitions));
 				swap_disklabel(lp);
 			} else
 				continue;
@@ -279,13 +282,14 @@ validate_label(mbr_args_t *a, daddr_t label_sector, size_t label_offset)
 				    label_offset, lp->d_npartitions);
 				continue;
 			}
+			checksum = dkcksum(lp);
 		}
 
 		/*
 		 * Disklabel is now in the right order and we have validated
 		 * the partition count, checksum it as the final check.
 		 */
-		if (dkcksum(lp) != 0) {
+		if (checksum != 0) {
 			aprint_error("%s: BSD disklabel @ %" PRId64
 			    "+%zd has bad checksum\n", a->pdk->dk_name,
 			    label_sector, label_offset);
diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
index 71b2a233bda5..3aeeb5a4d4bc 100644
--- a/sys/kern/subr_disk.c
+++ b/sys/kern/subr_disk.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_disk.c,v 1.83 2006/11/25 11:59:58 scw Exp $	*/
+/*	$NetBSD: subr_disk.c,v 1.84 2007/03/01 21:30:50 martin Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 1999, 2000 The NetBSD Foundation, Inc.
@@ -74,7 +74,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.83 2006/11/25 11:59:58 scw Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.84 2007/03/01 21:30:50 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -91,12 +91,18 @@ __KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.83 2006/11/25 11:59:58 scw Exp $");
  */
 u_int
 dkcksum(struct disklabel *lp)
+{
+	return dkcksum_sized(lp, lp->d_npartitions);
+}
+
+u_int
+dkcksum_sized(struct disklabel *lp, size_t npartitions)
 {
 	u_short *start, *end;
 	u_short sum = 0;
 
 	start = (u_short *)lp;
-	end = (u_short *)&lp->d_partitions[lp->d_npartitions];
+	end = (u_short *)&lp->d_partitions[npartitions];
 	while (start < end)
 		sum ^= *start++;
 	return (sum);
diff --git a/sys/sys/disklabel.h b/sys/sys/disklabel.h
index e87e3e4a8f50..ba4ef48b8fd4 100644
--- a/sys/sys/disklabel.h
+++ b/sys/sys/disklabel.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: disklabel.h,v 1.97 2005/12/29 14:53:47 tsutsui Exp $	*/
+/*	$NetBSD: disklabel.h,v 1.98 2007/03/01 21:30:50 martin Exp $	*/
 
 /*
  * Copyright (c) 1987, 1988, 1993
@@ -436,6 +436,7 @@ struct disk;
 void	 diskerr(const struct buf *, const char *, const char *, int,
 	    int, const struct disklabel *);
 u_int	 dkcksum(struct disklabel *);
+u_int	 dkcksum_sized(struct disklabel *, size_t);
 int	 setdisklabel(struct disklabel *, struct disklabel *, u_long,
 	    struct cpu_disklabel *);
 const char *readdisklabel(dev_t, void (*)(struct buf *),