diff --git a/Export/ExportInterface.php b/Export/ExportInterface.php
index e1efa4c05..c260649d1 100644
--- a/Export/ExportInterface.php
+++ b/Export/ExportInterface.php
@@ -61,10 +61,12 @@ interface ExportInterface extends ExportElementInterface
      * what the user is allowed to see. (Do not show personal data the user
      * is not allowed to see).
      * 
+     * The returned object should be an instance of QueryBuilder or NativeQuery.
+     * 
      * @param array $requiredModifiers
      * @param array $acl an array where each row has a `center` key containing the Chill\MainBundle\Entity\Center, and `circles` keys containing the reachable circles. Example: `array( array('center' => $centerA, 'circles' => array($circleA, $circleB) ) )`
      * @param array $data the data from the form, if any
-     * @return QueryBuilder the query to execute. 
+     * @return QueryBuilder|\Doctrine\ORM\NativeQuery the query to execute. 
      */
     public function initiateQuery(array $requiredModifiers, array $acl, array $data = array());