diff --git a/sys/ufs/ffs/ffs_snapshot.c b/sys/ufs/ffs/ffs_snapshot.c
index bfe89bfe8ee..db3c976ec2d 100644
--- a/sys/ufs/ffs/ffs_snapshot.c
+++ b/sys/ufs/ffs/ffs_snapshot.c
@@ -803,6 +803,7 @@ out1:
 		brelse(nbp);
 	} else {
 		loc = blkoff(fs, fs->fs_sblockloc);
+		copy_fs->fs_fmod = 0;
 		copy_fs->fs_ckhash = ffs_calc_sbhash(copy_fs);
 		bcopy((char *)copy_fs, &nbp->b_data[loc], (u_int)fs->fs_sbsize);
 		bawrite(nbp);