diff --git a/dnsapi/dns_lexicon.sh b/dnsapi/dns_lexicon.sh
index bceab8d5..4cec7cb7 100755
--- a/dnsapi/dns_lexicon.sh
+++ b/dnsapi/dns_lexicon.sh
@@ -29,7 +29,7 @@ dns_lexicon_add() {
   _savedomainconf PROVIDER "$PROVIDER"
   export PROVIDER
 
-  Lx_name=$(echo LEXICON_${PROVIDER}_USERNAME | tr [a-z] [A-Z])
+  Lx_name=$(echo LEXICON_${PROVIDER}_USERNAME | tr 'a-z' 'A-Z')
   eval Lx_name_v="\$$Lx_name"
   _debug "$Lx_name" "$Lx_name_v"
   if [ "$Lx_name_v" ]; then
@@ -37,7 +37,7 @@ dns_lexicon_add() {
     export "$Lx_name"
   fi
 
-  Lx_token=$(echo LEXICON_${PROVIDER}_TOKEN | tr [a-z] [A-Z])
+  Lx_token=$(echo LEXICON_${PROVIDER}_TOKEN | tr 'a-z' 'A-Z')
   eval Lx_token_v="\$$Lx_token"
   _debug "$Lx_token" "$Lx_token_v"
   if [ "$Lx_token_v" ]; then
@@ -45,7 +45,7 @@ dns_lexicon_add() {
     export "$Lx_token"
   fi
 
-  Lx_password=$(echo LEXICON_${PROVIDER}_PASSWORD | tr [a-z] [A-Z])
+  Lx_password=$(echo LEXICON_${PROVIDER}_PASSWORD | tr 'a-z' 'A-Z')
   eval Lx_password_v="\$$Lx_password"
   _debug "$Lx_password" "$Lx_password_v"
   if [ "$Lx_password_v" ]; then
@@ -53,7 +53,7 @@ dns_lexicon_add() {
     export "$Lx_password"
   fi
 
-  Lx_domaintoken=$(echo LEXICON_${PROVIDER}_DOMAINTOKEN | tr [a-z] [A-Z])
+  Lx_domaintoken=$(echo LEXICON_${PROVIDER}_DOMAINTOKEN | tr 'a-z' 'A-Z')
   eval Lx_domaintoken_v="\$$Lx_domaintoken"
   _debug "$Lx_domaintoken" "$Lx_domaintoken_v"
   if [ "$Lx_domaintoken_v" ]; then
diff --git a/dnsapi/dns_lua.sh b/dnsapi/dns_lua.sh
index a6375e5b..c03686ab 100755
--- a/dnsapi/dns_lua.sh
+++ b/dnsapi/dns_lua.sh
@@ -8,7 +8,7 @@
 #LUA_Email="user@luadns.net"
 
 LUA_Api="https://api.luadns.com/v1"
-LUA_auth=$(printf $LUA_Email:$LUA_Key | _base64)
+LUA_auth=$(printf "%s" "$LUA_Email:$LUA_Key" | _base64)
 
 ########  Public functions #####################
 
@@ -39,7 +39,7 @@ dns_lua_add() {
   _debug "Getting txt records"
   _LUA_rest GET "zones/${_domain_id}/records"
 
-  if ! printf "$response" | grep \"id\": >/dev/null; then
+  if ! _contains "$response" "\"id\":"; then
     _err "Error"
     return 1
   fi