diff --git a/usr/lib/ffdns/update-dns.sh b/usr/lib/ffdns/update-dns.sh
index eaa89ab..1691495 100755
--- a/usr/lib/ffdns/update-dns.sh
+++ b/usr/lib/ffdns/update-dns.sh
@@ -39,6 +39,8 @@ ForwardZones="$MasterDomain""/""$ZoneFilesFolder""db.""$FirstInternalView"".""$M
 
 SetupCache
 
+flock -n "$DNSSCRIPT_TEMP_FOLDER""script.lock" -c :
+
 CachedMasterFile="$DNSSCRIPT_TEMP_FOLDER""cache/db.""$MasterDomain"
 PreFetchMasterSerial="$(GetZoneFileSerial "$CachedMasterFile")"
 GetMasterFile