diff --git a/sys/nfs/nfs_bio.c b/sys/nfs/nfs_bio.c
index 3486a7884922..563389102396 100644
--- a/sys/nfs/nfs_bio.c
+++ b/sys/nfs/nfs_bio.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)nfs_bio.c	8.9 (Berkeley) 3/30/95
- * $Id: nfs_bio.c,v 1.57 1998/05/30 16:33:56 peter Exp $
+ * $Id: nfs_bio.c,v 1.58 1998/06/01 11:32:53 peter Exp $
  */
 
 
@@ -523,7 +523,7 @@ nfs_bioread(vp, uio, ioflag, cred, getpages)
 		    && uio->uio_offset >= np->n_direofoffset) {
 		    return (0);
 		}
-		lbn = uio->uio_offset / NFS_DIRBLKSIZ;
+		lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
 		on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
 		bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, p);
 		if (!bp)
diff --git a/sys/nfs/nfs_common.c b/sys/nfs/nfs_common.c
index b53f59d594ab..f256959d695a 100644
--- a/sys/nfs/nfs_common.c
+++ b/sys/nfs/nfs_common.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)nfs_subs.c  8.8 (Berkeley) 5/22/95
- * $Id: nfs_subs.c,v 1.60 1998/05/31 19:16:08 peter Exp $
+ * $Id: nfs_subs.c,v 1.61 1998/05/31 20:08:55 peter Exp $
  */
 
 /*
@@ -2011,11 +2011,11 @@ nfs_getcookie(np, off, add)
 	register struct nfsdmap *dp, *dp2;
 	register int pos;
 
-	pos = off / NFS_DIRBLKSIZ;
-	if (pos == 0) {
+	pos = (uoff_t)off / NFS_DIRBLKSIZ;
+	if (pos == 0 || off < 0) {
 #ifdef DIAGNOSTIC
 		if (add)
-			panic("nfs getcookie add at 0");
+			panic("nfs getcookie add at <= 0");
 #endif
 		return (&nfs_nullcookie);
 	}
diff --git a/sys/nfs/nfs_subs.c b/sys/nfs/nfs_subs.c
index b53f59d594ab..f256959d695a 100644
--- a/sys/nfs/nfs_subs.c
+++ b/sys/nfs/nfs_subs.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)nfs_subs.c  8.8 (Berkeley) 5/22/95
- * $Id: nfs_subs.c,v 1.60 1998/05/31 19:16:08 peter Exp $
+ * $Id: nfs_subs.c,v 1.61 1998/05/31 20:08:55 peter Exp $
  */
 
 /*
@@ -2011,11 +2011,11 @@ nfs_getcookie(np, off, add)
 	register struct nfsdmap *dp, *dp2;
 	register int pos;
 
-	pos = off / NFS_DIRBLKSIZ;
-	if (pos == 0) {
+	pos = (uoff_t)off / NFS_DIRBLKSIZ;
+	if (pos == 0 || off < 0) {
 #ifdef DIAGNOSTIC
 		if (add)
-			panic("nfs getcookie add at 0");
+			panic("nfs getcookie add at <= 0");
 #endif
 		return (&nfs_nullcookie);
 	}
diff --git a/sys/nfsclient/nfs_bio.c b/sys/nfsclient/nfs_bio.c
index 3486a7884922..563389102396 100644
--- a/sys/nfsclient/nfs_bio.c
+++ b/sys/nfsclient/nfs_bio.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)nfs_bio.c	8.9 (Berkeley) 3/30/95
- * $Id: nfs_bio.c,v 1.57 1998/05/30 16:33:56 peter Exp $
+ * $Id: nfs_bio.c,v 1.58 1998/06/01 11:32:53 peter Exp $
  */
 
 
@@ -523,7 +523,7 @@ nfs_bioread(vp, uio, ioflag, cred, getpages)
 		    && uio->uio_offset >= np->n_direofoffset) {
 		    return (0);
 		}
-		lbn = uio->uio_offset / NFS_DIRBLKSIZ;
+		lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
 		on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
 		bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, p);
 		if (!bp)
diff --git a/sys/nfsclient/nfs_subs.c b/sys/nfsclient/nfs_subs.c
index b53f59d594ab..f256959d695a 100644
--- a/sys/nfsclient/nfs_subs.c
+++ b/sys/nfsclient/nfs_subs.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)nfs_subs.c  8.8 (Berkeley) 5/22/95
- * $Id: nfs_subs.c,v 1.60 1998/05/31 19:16:08 peter Exp $
+ * $Id: nfs_subs.c,v 1.61 1998/05/31 20:08:55 peter Exp $
  */
 
 /*
@@ -2011,11 +2011,11 @@ nfs_getcookie(np, off, add)
 	register struct nfsdmap *dp, *dp2;
 	register int pos;
 
-	pos = off / NFS_DIRBLKSIZ;
-	if (pos == 0) {
+	pos = (uoff_t)off / NFS_DIRBLKSIZ;
+	if (pos == 0 || off < 0) {
 #ifdef DIAGNOSTIC
 		if (add)
-			panic("nfs getcookie add at 0");
+			panic("nfs getcookie add at <= 0");
 #endif
 		return (&nfs_nullcookie);
 	}
diff --git a/sys/nfsserver/nfs_srvsubs.c b/sys/nfsserver/nfs_srvsubs.c
index b53f59d594ab..f256959d695a 100644
--- a/sys/nfsserver/nfs_srvsubs.c
+++ b/sys/nfsserver/nfs_srvsubs.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)nfs_subs.c  8.8 (Berkeley) 5/22/95
- * $Id: nfs_subs.c,v 1.60 1998/05/31 19:16:08 peter Exp $
+ * $Id: nfs_subs.c,v 1.61 1998/05/31 20:08:55 peter Exp $
  */
 
 /*
@@ -2011,11 +2011,11 @@ nfs_getcookie(np, off, add)
 	register struct nfsdmap *dp, *dp2;
 	register int pos;
 
-	pos = off / NFS_DIRBLKSIZ;
-	if (pos == 0) {
+	pos = (uoff_t)off / NFS_DIRBLKSIZ;
+	if (pos == 0 || off < 0) {
 #ifdef DIAGNOSTIC
 		if (add)
-			panic("nfs getcookie add at 0");
+			panic("nfs getcookie add at <= 0");
 #endif
 		return (&nfs_nullcookie);
 	}