diff --git a/bt5/erp5_discussion/SkinTemplateItem/portal_skins/erp5_discussion/DiscussionThread_createNewDiscussionPost.xml b/bt5/erp5_discussion/SkinTemplateItem/portal_skins/erp5_discussion/DiscussionThread_createNewDiscussionPost.xml
index 8f3b918c87d9fa46eab39fdfb803e2a1f7ec3c19..2e039b5c3adbf515426957d828812fc8a4b1351c 100644
--- a/bt5/erp5_discussion/SkinTemplateItem/portal_skins/erp5_discussion/DiscussionThread_createNewDiscussionPost.xml
+++ b/bt5/erp5_discussion/SkinTemplateItem/portal_skins/erp5_discussion/DiscussionThread_createNewDiscussionPost.xml
@@ -72,6 +72,10 @@ discussion_post = context.newContent(\n
 # depending on security model Post can be submited for review\n
 portal_status_message = "New post created in background."\n
 \n
+# a parent thread is actually just a logical container so it\'s modified\n
+# whenever a new post is done\n
+context.edit(modification_date = DateTime())\n
+\n
 return context.Base_redirect(form_id,\n
          keep_items = dict(portal_status_message=context.Base_translateString(portal_status_message)))\n
 </string> </value>
diff --git a/bt5/erp5_discussion/bt/revision b/bt5/erp5_discussion/bt/revision
index 97a55e1d749c6ac7c783778b6ea2d19cb770909d..0aede4a000a9fda5ae3bb7cad217748e1392f17c 100644
--- a/bt5/erp5_discussion/bt/revision
+++ b/bt5/erp5_discussion/bt/revision
@@ -1 +1 @@
-101
\ No newline at end of file
+102
\ No newline at end of file