Index: django/contrib/syndication/feeds.py
===================================================================
--- django/contrib/syndication/feeds.py	(revision 5065)
+++ django/contrib/syndication/feeds.py	(working copy)
@@ -93,6 +93,9 @@
 
         for item in self.__get_dynamic_attr('items', obj):
             link = add_domain(current_site.domain, self.__get_dynamic_attr('item_link', item))
+            unique_id = self.__get_dynamic_attr('item_guid', item)
+            if not unique_id:
+                unique_id = link
             enc = None
             enc_url = self.__get_dynamic_attr('item_enclosure_url', item)
             if enc_url:
@@ -111,7 +114,7 @@
                 title = title_tmp.render(Context({'obj': item, 'site': current_site})).decode('utf-8'),
                 link = link,
                 description = description_tmp.render(Context({'obj': item, 'site': current_site})).decode('utf-8'),
-                unique_id = link,
+                unique_id = unique_id,
                 enclosure = enc,
                 pubdate = self.__get_dynamic_attr('item_pubdate', item),
                 author_name = author_name,