diff --git a/dnsapi/dns_ipv64.sh b/dnsapi/dns_ipv64.sh
index 9979be42..afa6df5a 100755
--- a/dnsapi/dns_ipv64.sh
+++ b/dnsapi/dns_ipv64.sh
@@ -36,6 +36,10 @@ dns_ipv64_add() {
   _debug _sub_domain "$_sub_domain"
   _debug _domain "$_domain"
 
+  # convert to lower case
+  _domain = $(echo "$_domain" | tr '[:upper:]' '[:lower:]')
+  _sub_domain = $(echo "$_sub_domain" | tr '[:upper:]' '[:lower:]')
+
   # Now add the TXT record
   _info "Trying to add TXT record"
   if _ipv64_rest "POST" "add_record=$_domain&praefix=$_sub_domain&type=TXT&content=$txtvalue"; then
@@ -70,6 +74,10 @@ dns_ipv64_rm() {
   _debug _sub_domain "$_sub_domain"
   _debug _domain "$_domain"
 
+  # convert to lower case
+  _domain = $(echo "$_domain" | tr '[:upper:]' '[:lower:]')
+  _sub_domain = $(echo "$_sub_domain" | tr '[:upper:]' '[:lower:]')
+  
   # Now delete the TXT record
   _info "Trying to delete TXT record"
   if _ipv64_rest "DELETE" "del_record=$_domain&praefix=$_sub_domain&type=TXT&content=$txtvalue"; then