diff --git a/vas/rest/ws/vitis/File_downloader.class.inc b/vas/rest/ws/vitis/File_downloader.class.inc
index 3acbf9e04a793a3e74fb44416de0c6cf652d6f57..bb8749da4a18c2e8fb2361355079dfbfdd8d98de 100755
--- a/vas/rest/ws/vitis/File_downloader.class.inc
+++ b/vas/rest/ws/vitis/File_downloader.class.inc
@@ -110,6 +110,7 @@ class File_downloader extends Vitis {
                   header("Content-Type: " . $sContentType);
                   header("Content-disposition: attachment; filename=\"" . $sFileName . "\"");
                   header('Content-Length: ' . filesize($sPath));
+                  header('Content-Length: ' . $this->oFilesManager->oFileInterface->filesize($sPath));
                   if ($sContentType === "application/octet-stream") {
                     header("Content-Transfer-Encoding: Binary");
                   }