diff --git a/framework/web/UploadedFile.php b/framework/web/UploadedFile.php
index 6eadebc295..cd8d2f8b08 100644
--- a/framework/web/UploadedFile.php
+++ b/framework/web/UploadedFile.php
@@ -74,7 +74,7 @@ class UploadedFile extends Object
      * @param \yii\base\Model $model the data model
      * @param string $attribute the attribute name. The attribute name may contain array indexes.
      * For example, '[1]file' for tabular file uploading; and 'file[1]' for an element in a file array.
-     * @return UploadedFile the instance of the uploaded file.
+     * @return null|UploadedFile the instance of the uploaded file.
      * Null is returned if no file is uploaded for the specified model attribute.
      * @see getInstanceByName()
      */
@@ -102,7 +102,7 @@ class UploadedFile extends Object
      * Returns an uploaded file according to the given file input name.
      * The name can be a plain string or a string like an array element (e.g. 'Post[imageFile]', or 'Post[0][imageFile]').
      * @param string $name the name of the file input field.
-     * @return UploadedFile the instance of the uploaded file.
+     * @return null|UploadedFile the instance of the uploaded file.
      * Null is returned if no file is uploaded for the specified name.
      */
     public static function getInstanceByName($name)