diff --git a/dnsapi/dns_cyon.sh b/dnsapi/dns_cyon.sh
index 0ced421..c096d8b 100644
--- a/dnsapi/dns_cyon.sh
+++ b/dnsapi/dns_cyon.sh
@@ -81,6 +81,7 @@ _cyon_is_idn() {
 
 _cyon_load_parameters() {
   # Read the required parameters to add the TXT entry.
+  # shellcheck disable=SC2018,SC2019
   fulldomain="$(printf "%s" "${1}" | tr "A-Z" "a-z")"
   fulldomain_idn="${fulldomain}"