diff --git a/app/bin/home/backup b/app/bin/home/backup
index b4ab1d9..c2d0c06 100755
--- a/app/bin/home/backup
+++ b/app/bin/home/backup
@@ -4,6 +4,7 @@
 
 source /var/roothome/.config/bash/module/notify.sh
 source /var/roothome/.config/bash/module/checksum.sh
+source /var/roothome/.config/bash/module/recursive.sh
 
 dow=$(/usr/bin/date +%u)                                                 # current day of week number.
 date=$(/usr/bin/date +%Y%m%d%H%M)                                        # date stamp.
@@ -42,9 +43,9 @@ rm $path_docker/${dow}_*.tgz
 /usr/bin/tar --exclude-from=docker/.tarignore -c docker | /usr/bin/gzip -1 > $path_docker/docker.tgz && mv $path_docker/docker.tgz $path_docker/${dow}_${date}-$(/usr/bin/sha1sum $path_docker/docker.tgz | cut -d\  -f1).tgz || notify 'backup : docker failed'
 
 # Update checksums.
-cd /var/mnt/storage/hot/media/book/  && checksum_create || notify 'Backup : checksum book failed.'
-cd /var/mnt/storage/hot/media/music/ && checksum_create || notify 'Backup : checksum book failed.'
-cd /var/mnt/storage/hot/media/paper/ && checksum_create || notify 'Backup : checksum book failed.'
+cd /var/mnt/storage/hot/media/book/  && recursive checksum_create || notify 'Backup : checksum book failed.'
+cd /var/mnt/storage/hot/media/music/ && recursive checksum_create || notify 'Backup : checksum book failed.'
+cd /var/mnt/storage/hot/media/paper/ && recursive checksum_create || notify 'Backup : checksum book failed.'
 
 # copy media.
 /usr/bin/rsync -a --delete /var/mnt/storage/hot/media/book/            /var/mnt/backup/backup/tmp/book/    || notify 'backup : copy book failed'