diff --git a/HTMLFormatter.py b/HTMLFormatter.py
index 4788fd8..e8822a4 100644
--- a/HTMLFormatter.py
+++ b/HTMLFormatter.py
@@ -77,7 +77,7 @@ class XMLishFormatter (BaseFormatter.BaseFormatter):
 
             # these are used as relative links
             if file_.generated and not file_.filetype.startswith ('cover.'):
-                file_.filename = "ebooks/%d.%s" % (file_.id, file_.filetype)
+                file_.filename = "ebooks/%d.%s" % (dc.project_gutenberg_id, file_.filetype)
                 if m in HANDOVER_TYPES:
                     file_.filename = file_.filename + '?' + urllib.parse.urlencode (
                         { 'session_id': str (cherrypy.session.id) } )