diff --git a/src/Api/Serializer/BasicDiscussionSerializer.php b/src/Api/Serializer/BasicDiscussionSerializer.php
index 5a7b758f47..aa8079fd3f 100644
--- a/src/Api/Serializer/BasicDiscussionSerializer.php
+++ b/src/Api/Serializer/BasicDiscussionSerializer.php
@@ -36,7 +36,7 @@ protected function getDefaultAttributes($discussion)
         return [
             'title' => $discussion->title,
             'slug'  => $discussion->slug,
-            'idWithSlug' => $discussion->id.trim($discussion->slug) ? '-'.$discussion->slug : ''
+            'idWithSlug' => $discussion->id.(trim($discussion->slug) ? '-'.$discussion->slug : '')
         ];
     }