diff --git a/vas/rest/ws/vitis/File_downloader.class.inc b/vas/rest/ws/vitis/File_downloader.class.inc
index 2fab279f3a65052cd40f379b6b9faf67126addb3..16451128beb039051213d5ba502cbd9285c71d12 100644
--- a/vas/rest/ws/vitis/File_downloader.class.inc
+++ b/vas/rest/ws/vitis/File_downloader.class.inc
@@ -128,7 +128,10 @@ class File_downloader extends Vitis {
 
           } else {
             // modification de $sPath pour aller chercher le fichier dans ws_data
-            $sPath = $this->aProperties["ws_data_dir"] . "/" . $this->aValues["key"];
+            if (strpos($this->aValues["key"], 'ws_data') === 0)
+              $sPath = str_replace('ws_data', $this->aProperties['ws_data_dir'], $this->aValues["key"]);
+            else
+              $sPath = $this->aProperties["ws_data_dir"] . "/" . $this->aValues["key"];
             // check eTag
             $sEtag = sha1(file_get_contents($sPath), false);