diff --git a/plugins/zfs/zfs_list b/plugins/zfs/zfs_list
index c7abf7da..7307f9d5 100755
--- a/plugins/zfs/zfs_list
+++ b/plugins/zfs/zfs_list
@@ -79,6 +79,12 @@ for i in `zfs list -Hp | awk '{print $1}'`; do
 	values=( $(zfs get -p usedbydataset,usedbychildren,usedbysnapshots,usedbyrefreservation,available,quota $i | awk 'BEGIN {total=0;} { if( NR==1 ) next; } !/quota/ {total=total+$3;} {print $3} END{print total;}') )
 	fsname=$(clean_fieldname $(echo "$i" | sed 's/\//__/g'))
 
+	if [ ${values[5]} = "-" ]; then
+		quota=0
+	else
+		quota=${values[5]}
+	fi
+
 	echo <<EOF "multigraph zfs_list_$fsname
 usedbydataset.value ${values[0]}
 usedbysnapshots.value ${values[2]}
@@ -86,7 +92,7 @@ usedbychildren.value ${values[1]}
 usedbyrefreservation.value ${values[3]}
 available.value ${values[4]}
 total.value ${values[6]}
-quota.value ${values[5]}"
+quota.value $quota"
 EOF
 done