diff --git a/sys/fs/tmpfs/tmpfs.h b/sys/fs/tmpfs/tmpfs.h
--- a/sys/fs/tmpfs/tmpfs.h
+++ b/sys/fs/tmpfs/tmpfs.h
@@ -216,7 +216,7 @@
 	struct timespec		tn_mtime;	/* (vi) */
 	struct timespec		tn_ctime;	/* (vi) */
 	struct timespec		tn_birthtime;	/* (v) */
-	unsigned long		tn_gen;		/* (c) */
+	unsigned int		tn_gen;		/* (c) */
 
 	/*
 	 * As there is a single vnode for each active file within the
@@ -448,11 +448,10 @@
  * NFS code.
  */
 struct tmpfs_fid_data {
+	unsigned short		tfd_len;
+	unsigned int		tfd_gen;
 	ino_t			tfd_id;
-	unsigned long		tfd_gen;
 };
-_Static_assert(sizeof(struct tmpfs_fid_data) <= MAXFIDSZ,
-    "(struct tmpfs_fid_data) is larger than (struct fid).fid_data");
 
 struct tmpfs_dir_cursor {
 	struct tmpfs_dirent	*tdc_current;
diff --git a/sys/fs/tmpfs/tmpfs_vfsops.c b/sys/fs/tmpfs/tmpfs_vfsops.c
--- a/sys/fs/tmpfs/tmpfs_vfsops.c
+++ b/sys/fs/tmpfs/tmpfs_vfsops.c
@@ -585,29 +585,25 @@
 tmpfs_fhtovp(struct mount *mp, struct fid *fhp, int flags,
     struct vnode **vpp)
 {
-	struct tmpfs_fid_data tfd;
+	struct tmpfs_fid_data *tfd;
 	struct tmpfs_mount *tmp;
 	struct tmpfs_node *node;
 	int error;
 
-	if (fhp->fid_len != sizeof(tfd))
+	if (fhp->fid_len != sizeof(*tfd))
 		return (EINVAL);
 
-	/*
-	 * Copy from fid_data onto the stack to avoid unaligned pointer use.
-	 * See the comment in sys/mount.h on struct fid for details.
-	 */
-	memcpy(&tfd, fhp->fid_data, fhp->fid_len);
+	tfd = (struct tmpfs_fid_data *)fhp;
 
 	tmp = VFS_TO_TMPFS(mp);
 
-	if (tfd.tfd_id >= tmp->tm_nodes_max)
+	if (tfd->tfd_id >= tmp->tm_nodes_max)
 		return (EINVAL);
 
 	TMPFS_LOCK(tmp);
 	LIST_FOREACH(node, &tmp->tm_nodes_used, tn_entries) {
-		if (node->tn_id == tfd.tfd_id &&
-		    node->tn_gen == tfd.tfd_gen) {
+		if (node->tn_id == tfd->tfd_id &&
+		    node->tn_gen == tfd->tfd_gen) {
 			tmpfs_ref_node(node);
 			break;
 		}
diff --git a/sys/fs/tmpfs/tmpfs_vnops.c b/sys/fs/tmpfs/tmpfs_vnops.c
--- a/sys/fs/tmpfs/tmpfs_vnops.c
+++ b/sys/fs/tmpfs/tmpfs_vnops.c
@@ -1706,23 +1706,15 @@
 };
 */
 {
-	struct tmpfs_fid_data tfd;
+	struct tmpfs_fid_data *const tfd = (struct tmpfs_fid_data *)ap->a_fhp;
 	struct tmpfs_node *node;
-	struct fid *fhp;
-	_Static_assert(sizeof(struct tmpfs_fid_data) <= sizeof(struct fid),
+	_Static_assert(sizeof(*tfd) <= sizeof(struct fid),
 	    "struct tmpfs_fid_data cannot be larger than struct fid");
 
 	node = VP_TO_TMPFS_NODE(ap->a_vp);
-	fhp = ap->a_fhp;
-	fhp->fid_len = sizeof(tfd);
-
-	/*
-	 * Copy into fid_data from the stack to avoid unaligned pointer use.
-	 * See the comment in sys/mount.h on struct fid for details.
-	 */
-	tfd.tfd_id = node->tn_id;
-	tfd.tfd_gen = node->tn_gen;
-	memcpy(fhp->fid_data, &tfd, fhp->fid_len);
+	tfd->tfd_len = sizeof(*tfd);
+	tfd->tfd_gen = node->tn_gen;
+	tfd->tfd_id = node->tn_id;
 
 	return (0);
 }