diff --git a/product/ERP5/Document/File.py b/product/ERP5/Document/File.py
index 8157d897710bd362231cde213068628cc9667b4f..6fbea44ffb298ef0bd6535dad9e9d7d7fbf6783f 100644
--- a/product/ERP5/Document/File.py
+++ b/product/ERP5/Document/File.py
@@ -84,6 +84,7 @@ class File(Document, CMFFile, ConversionCacheMixin):
 
   # Default global values
   content_type = '' # Required for WebDAV support (default value)
+  data = 'Empty File' # A hack required to use OFS.Image.index_html without calling OFS.Image.__init__
 
   # Default Properties
   property_sheets = ( PropertySheet.Base