diff --git a/libvirt-zsh-backup.sh b/libvirt-zsh-backup.sh
index b3ace78..4230444 100644
--- a/libvirt-zsh-backup.sh
+++ b/libvirt-zsh-backup.sh
@@ -3,7 +3,7 @@
 helpFunction()
 {
    echo ""
-   echo "Usage: $0 -v VmName -t TargetHost -d TargetDataset"
+   echo "Usage: $0 -v VmName -t TargetHost -d TargetDataset -l LIMIT"
    echo -e "\t-v Name of the vm to backup"
    echo -e "\t-t Backup target host name"
    echo -e "\t-s VM source zfs dataset"
@@ -100,6 +100,7 @@ if [ $? -eq 0 ]
 then
     zfs set backup:success="true" $SRCZFS
     zfs set backup:date="$DATE" $SRCZFS
+    zfs destroy "$SRCZFS"@"$LASTSNAP"
 else
     zfs set backup:success="false" $SRCZFS
     zfs set backup:failed="$DATE" $SRCZFS