diff --git a/action.php b/action.php
index b755f19..e70c1d1 100644
--- a/action.php
+++ b/action.php
@@ -100,7 +100,8 @@ public function translateJS(Event $event)
 
         $count = count($event->data['script']);
         for ($i = 0; $i < $count; $i++) {
-            if (strpos($event->data['script'][$i]['src'], '/lib/exe/js.php') !== false) {
+            if (array_key_exists('src', $event->data['script'][$i]) &&
+                strpos($event->data['script'][$i]['src'], '/lib/exe/js.php') !== false) {
                 $event->data['script'][$i]['src'] .= '&lang=' . hsc($conf['lang']);
             }
         }