diff --git a/book.php b/book.php
index 10237e7..a0e6c34 100644
--- a/book.php
+++ b/book.php
@@ -427,7 +427,7 @@ class Book extends Base {
         {
             if ($data->isKnownType ())
             {
-                array_push ($linkArray, $data->getDataLink (Link::OPDS_ACQUISITION_TYPE, "Download"));
+                array_push ($linkArray, $data->getDataLink (Link::OPDS_ACQUISITION_TYPE, $data->format));
             }
         }