diff --git a/scripts/pi-hole/php/add.php b/scripts/pi-hole/php/add.php
index d6059a51..94da8863 100644
--- a/scripts/pi-hole/php/add.php
+++ b/scripts/pi-hole/php/add.php
@@ -16,17 +16,23 @@ if (empty($api)) {
     list_verify($list);
 }
 
+// Split individual domains into array
+$domains = preg_split('/\s+/', trim($_POST['domain']));
+$comment = trim($_POST['comment']);
+
+// Convert domain name to IDNA ASCII form for international domains
+foreach($domains as &$domain)
+{
+	$domain = idn_to_ascii($domain);
+}
+
 // Only check domains we add to the exact lists.
 // Regex are validated by FTL during import
 $check_lists = ["white","black","audit"];
 if(in_array($list, $check_lists)) {
-    check_domain();
+    check_domain($domains);
 }
 
-// Split individual domains into array
-$domains = preg_split('/\s+/', trim($_POST['domain']));
-$comment = trim($_POST['comment']);
-
 require_once("func.php");
 require_once("database.php");
 $GRAVITYDB = getGravityDBFilename();
diff --git a/scripts/pi-hole/php/auth.php b/scripts/pi-hole/php/auth.php
index 56f84520..7398cbdf 100644
--- a/scripts/pi-hole/php/auth.php
+++ b/scripts/pi-hole/php/auth.php
@@ -113,15 +113,12 @@ function check_csrf($token) {
     }
 }
 
-function check_domain() {
-    if(isset($_POST['domain'])){
-        $domains = preg_split('/\s+/', $_POST['domain']);
-        foreach($domains as $domain)
-        {
-            $validDomain = is_valid_domain_name($domain);
-            if(!$validDomain){
-                log_and_die(htmlspecialchars($domain. ' is not a valid domain'));
-            }
+function check_domain(&$domains) {
+    foreach($domains as &$domain)
+    {
+        $validDomain = is_valid_domain_name($domain);
+        if(!$validDomain){
+            log_and_die(htmlspecialchars($domain. ' is not a valid domain'));
         }
     }
 }
diff --git a/scripts/pi-hole/php/get.php b/scripts/pi-hole/php/get.php
index f47f2c84..5a230bdb 100644
--- a/scripts/pi-hole/php/get.php
+++ b/scripts/pi-hole/php/get.php
@@ -30,6 +30,13 @@ function getTableContent($type) {
 
 	while($results !== false && $res = $results->fetchArray(SQLITE3_ASSOC))
 	{
+		$utf8_domain = idn_to_utf8($res['domain']);
+		// Convert domain name to international form
+		// if applicable
+		if($res['domain'] !== $utf8_domain)
+		{
+			$res['domain'] = $utf8_domain.' ('.$res['domain'].')';
+		}
 		array_push($entries, $res);
 	}
 
diff --git a/scripts/pi-hole/php/groups.php b/scripts/pi-hole/php/groups.php
index ff6f7aa5..fcea7e22 100644
--- a/scripts/pi-hole/php/groups.php
+++ b/scripts/pi-hole/php/groups.php
@@ -346,6 +346,13 @@ if ($_POST['action'] == 'get_groups') {
                 array_push($groups, $gres['group_id']);
             }
             $res['groups'] = $groups;
+            $utf8_domain = idn_to_utf8($res['domain']);
+            // Convert domain name to international form
+            // if applicable
+            if($res['domain'] !== $utf8_domain)
+            {
+                $res['domain'] = $utf8_domain.' ('.$res['domain'].')';
+            }
             array_push($data, $res);
         }
 
@@ -364,7 +371,8 @@ if ($_POST['action'] == 'get_groups') {
 
         $type = intval($_POST['type']);
 
-        $domain = $_POST['domain'];
+        // Convert domain name to IDNA ASCII form for international domains
+        $domain = idn_to_ascii($_POST['domain']);
         if($type === ListType::whitelist || $type === ListType::blacklist)
         {
             // If adding to the exact lists, we convert the domain lower case and check whether it is valid