diff --git a/sys/fs/cd9660/cd9660_vnops.c b/sys/fs/cd9660/cd9660_vnops.c
index c18b664d25f..d227e4a9d3d 100644
--- a/sys/fs/cd9660/cd9660_vnops.c
+++ b/sys/fs/cd9660/cd9660_vnops.c
@@ -737,6 +737,7 @@ cd9660_strategy(ap)
 	}
 	vp = ip->i_devvp;
 	bp->b_dev = vp->v_rdev;
+	bp->b_offset = dbtob(bp->b_blkno);
 	VOP_SPECSTRATEGY(vp, bp);
 	return (0);
 }
diff --git a/sys/isofs/cd9660/cd9660_vnops.c b/sys/isofs/cd9660/cd9660_vnops.c
index c18b664d25f..d227e4a9d3d 100644
--- a/sys/isofs/cd9660/cd9660_vnops.c
+++ b/sys/isofs/cd9660/cd9660_vnops.c
@@ -737,6 +737,7 @@ cd9660_strategy(ap)
 	}
 	vp = ip->i_devvp;
 	bp->b_dev = vp->v_rdev;
+	bp->b_offset = dbtob(bp->b_blkno);
 	VOP_SPECSTRATEGY(vp, bp);
 	return (0);
 }