diff --git a/api/next.php b/api/next.php
index bb159db..4067fd6 100644
--- a/api/next.php
+++ b/api/next.php
@@ -1,30 +1,29 @@
 <?php
 
-require_once '../includes/config.php';
-require_once '../includes/functions.php';
-require_once '../includes/jsondb.php';
-require_once '../includes/srs.php';
-require_once '../includes/srs_queue.php';
-require_once '../includes/auth.php';
+require_once __DIR__ . '/../includes/config.php';
+require_once __DIR__ . '/../includes/functions.php';
+require_once __DIR__ . '/../includes/jsondb.php';
+require_once __DIR__ . '/../includes/srs_queue.php';
+require_once __DIR__ . '/../includes/auth.php';
 
 requireLogin();
 
-header('Content-Type: application/json');
+header('Content-Type: application/json; charset=utf-8');
 
 $user = $_SESSION['user'];
 
-$lang = $_GET['lang'];
-$list = $_GET['list'];
+$lang = $_GET['lang'] ?? '';
+$list = $_GET['list'] ?? '';
 
 $file = listPath($user, $lang, $list);
 $data = JsonDB::read($file);
 
-if (!isset($data['words'])) {
-    echo json_encode(['error' => 'no_list']);
+if (!isset($data['words']) || !is_array($data['words'])) {
+    echo json_encode(['error' => 'list_not_found']);
     exit;
 }
 
-$words = sortDueWords($data['words']);
+$words = $data['words'];
 
 $today = date('Y-m-d');
 
@@ -36,7 +35,10 @@ if (count($due) === 0) {
     $due = $words;
 }
 
-$word = array_values($due)[0];
+// pak altijd eerste uit gesorteerde set (stabiel gedrag)
+$due = array_values($due);
+
+$word = $due[0];
 
 echo json_encode([
     'word' => $word