diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 01afcd9701a9..a801728c721e 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -340,9 +340,9 @@ sequential_heuristic(struct uio *uio, struct file *fp)
 		 * are.
 		 */
 		fp->f_seqcount += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE;
-		if (fp->f_seqcount >= 127)
-			fp->f_seqcount = 127;
-		return(fp->f_seqcount << 16);
+		if (fp->f_seqcount > IO_SEQMAX)
+			fp->f_seqcount = IO_SEQMAX;
+		return(fp->f_seqcount << IO_SEQSHIFT);
 	}
 
 	/*
diff --git a/sys/nfsserver/nfs_serv.c b/sys/nfsserver/nfs_serv.c
index 97936d1d0a62..19fc992a2a81 100644
--- a/sys/nfsserver/nfs_serv.c
+++ b/sys/nfsserver/nfs_serv.c
@@ -861,8 +861,8 @@ nfsrv_read(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
 		 */
 
 		if ((off == 0 && nh->nh_seqcount > 0) || off == nh->nh_nextr) {
-			if (++nh->nh_seqcount > 127)
-				nh->nh_seqcount = 127;
+			if (++nh->nh_seqcount > IO_SEQMAX)
+				nh->nh_seqcount = IO_SEQMAX;
 		} else if (nh->nh_seqcount > 1) {
 			nh->nh_seqcount = 1;
 		} else {
@@ -871,7 +871,7 @@ nfsrv_read(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
 		nh->nh_use += NHUSE_INC;
 		if (nh->nh_use > NHUSE_MAX)
 			nh->nh_use = NHUSE_MAX;
-		ioflag |= nh->nh_seqcount << 16;
+		ioflag |= nh->nh_seqcount << IO_SEQSHIFT;
         }
 
 	nfsm_reply(NFSX_POSTOPORFATTR(v3) + 3 * NFSX_UNSIGNED+nfsm_rndup(cnt));
diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h
index 44af2bc0e5b2..fd7e6c4dd2cb 100644
--- a/sys/sys/vnode.h
+++ b/sys/sys/vnode.h
@@ -281,6 +281,9 @@ struct vattr {
 #define	IO_NORMAL	0x0800		/* operate on regular data */
 #define	IO_NOMACCHECK	0x1000		/* MAC checks unnecessary */
 
+#define IO_SEQMAX	0x7F		/* seq heuristic max value */
+#define IO_SEQSHIFT	16		/* seq heuristic in upper 16 bits */
+
 /*
  *  Modes.  Some values same as Ixxx entries from inode.h for now.
  */