diff --git a/UploadBehavior.php b/UploadBehavior.php
index b3d359c..351bddd 100644
--- a/UploadBehavior.php
+++ b/UploadBehavior.php
@@ -8,6 +8,7 @@
 use yii\base\InvalidConfigException;
 use yii\base\InvalidParamException;
 use yii\db\BaseActiveRecord;
+use yii\helpers\ArrayHelper;
 use yii\helpers\FileHelper;
 use yii\web\UploadedFile;