diff --git a/src/scripts/backup_nocloud.sh b/src/scripts/backup_nocloud.sh
index 2a5a30ece3f435823e09045a2ed03545e91a4012..c77d8958096a4e1ac12b3a75c0cf0226c320d00c 100755
--- a/src/scripts/backup_nocloud.sh
+++ b/src/scripts/backup_nocloud.sh
@@ -304,6 +304,7 @@ do_log "démarrage le `date`"
 
 if $luks
 then
+    cryptsetup luksClose $luksname
     echo $ENCPASS | cryptsetup luksOpen $dev $luksname
     test_and_fail $? "Impossible de déchiffrer le disque, abandon"
     /bin/mount -t auto /dev/mapper/$luksname $dest