diff --git a/libguestfs.mkinitrd.boot.sh b/libguestfs.mkinitrd.boot.sh
index 22637c3..2cd04e5 100644
--- a/libguestfs.mkinitrd.boot.sh
+++ b/libguestfs.mkinitrd.boot.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 #%stage: block
 #
-#%modules: dm-mod virtio_blk virtio_console virtio_net virtio_pci virtio_scsi sg sd_mod sr_mod 9p cramfs ecryptfs ext2 ext3 fat fuse hfs hfsplus jfs minix ncpfs nfs quota reiserfs squashfs squashfs3 udf ufs xfs
+#%modules: dm-mod virtio_blk virtio_console virtio_net virtio_pci virtio_scsi sg sd_mod sr_mod 9p btrfs cramfs ecryptfs ext2 ext3 ext4 fat fuse hfs hfsplus jfs minix ncpfs nfs quota reiserfs squashfs squashfs3 udf ufs xfs
 #
 #%programs: mdadm
 #%programs: modprobe