diff --git a/example-dns-01-nsupdate-script.md b/example-dns-01-nsupdate-script.md
index ba3a013..2a68fc5 100644
--- a/example-dns-01-nsupdate-script.md
+++ b/example-dns-01-nsupdate-script.md
@@ -16,14 +16,16 @@ set -u
 set -o pipefail
 
 NSUPDATE="nsupdate -k /path/to/Kdnsupdatekey.private"
+DNSSERVER="127.0.0.1"
+ZONE="mydomain.com"
 TTL=300
 
 case "$1" in
     "deploy_challenge")
-        printf "update add _acme-challenge.%s. %d in TXT \"%s\"\n\n" "${2}" "${TTL}" "${4}" | $NSUPDATE
+        printf "server %s\nzone %s.\nupdate add _acme-challenge.%s. %d in TXT \"%s\"\nsend\n" "${DNSSERVER}" "${ZONE}" "${2}" "${TTL}" "${4}" | $NSUPDATE
         ;;
     "clean_challenge")
-        printf "update delete _acme-challenge.%s. %d in TXT \"%s\"\n\n" "${2}" "${TTL}" "${4}" | $NSUPDATE
+        printf "server %s\nzone %s.\nupdate delete _acme-challenge.%s. %d in TXT \"%s\"\nsend\n" "${DNSSERVER}" "${ZONE}" "${2}" "${TTL}" "${4}" | $NSUPDATE
         ;;
     "deploy_cert")
         # do nothing for now