diff --git a/dnsapi/dns_ispconfig.sh b/dnsapi/dns_ispconfig.sh
index 1e500ad..c8f7eed 100755
--- a/dnsapi/dns_ispconfig.sh
+++ b/dnsapi/dns_ispconfig.sh
@@ -128,7 +128,7 @@ _ISPC_addTxt() {
   curSerial="$(date +%s)"
   curStamp="$(date +'%F %T')"
   params="\"server_id\":\"${server_id}\",\"zone\":\"${zone}\",\"name\":\"${fulldomain}.\",\"type\":\"txt\",\"data\":\"${txtvalue}\",\"aux\":\"0\",\"ttl\":\"3600\",\"active\":\"y\",\"stamp\":\"${curStamp}\",\"serial\":\"${curSerial}\""
-  curData="{\"session_id\":\"${sessionID}\",\"client_id\":\"${client_id}\",\"params\":{${params}}}"
+  curData="{\"session_id\":\"${sessionID}\",\"client_id\":\"${client_id}\",\"params\":{${params}},\"update_serial\":true}}"
   curResult="$(_post "${curData}" "${ISPC_Api}?dns_txt_add")"
   _debug "Calling _ISPC_addTxt: '${curData}' '${ISPC_Api}?dns_txt_add'"
   _debug "Result of _ISPC_addTxt: '$curResult'"