diff --git a/Models/QAQuestion.php b/Models/QAQuestion.php
index f078825..058fb1e 100755
--- a/Models/QAQuestion.php
+++ b/Models/QAQuestion.php
@@ -19,6 +19,7 @@ use Modules\Profile\Models\NullProfile;
 use Modules\Profile\Models\Profile;
 use Modules\Tag\Models\Tag;
 use phpOMS\Localization\ISO639x1Enum;
+use Modules\Tag\Models\NullTag;
 
 /**
  * QA question class.