diff --git a/CHANGES.txt b/CHANGES.txt
index 3d64c0c..20142a1 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -4,6 +4,10 @@ Changelog
 1.0RC1 (unreleased)
 -------------------
 
+- Make sure comment UIDs in the catalog are always unique. This fixes  
+  http://dev.plone.org/plone/ticket/10652. 
+  [timo] 
+
 - Fix 'check all' on batch moderation page.
   [davisagli]
 
diff --git a/plone/app/discussion/configure.zcml b/plone/app/discussion/configure.zcml
index e7b9d2f..ef2b4e6 100644
--- a/plone/app/discussion/configure.zcml
+++ b/plone/app/discussion/configure.zcml
@@ -10,7 +10,9 @@
     <five:registerPackage package="." />
 
     <include package="plone.indexer" />
-
+    <include package="plone.uuid" />
+    <include package="plone.app.uuid" />
+    
     <include file="permissions.zcml" />
     <include file="notifications.zcml" />
     <include file="subscribers.zcml" />
@@ -43,6 +45,7 @@
     <!-- Comments -->
 
     <class class=".comment.Comment">
+        <implements interface="plone.uuid.interfaces.IAttributeUUID" />
         <require interface=".interfaces.IComment" permission="zope2.View" />
         <require attributes="Title Creator getId getText" permission="zope2.View" />
     </class>
diff --git a/plone/app/discussion/conversation.py b/plone/app/discussion/conversation.py
index 1887e9e..52936dd 100644
--- a/plone/app/discussion/conversation.py
+++ b/plone/app/discussion/conversation.py
@@ -41,6 +41,7 @@ from zope.container.contained import ContainerModifiedEvent
 try:
     # Plone 4
     from zope.lifecycleevent import ObjectAddedEvent
+    from zope.lifecycleevent import ObjectCreatedEvent
     from zope.lifecycleevent import ObjectRemovedEvent
 except ImportError: # pragma: no cover
     # Plone 3.x
@@ -252,6 +253,7 @@ class Conversation(Traversable, Persistent, Explicit):
 
         # Notify that the object is added. The object must here be
         # acquisition wrapped or the indexing will fail.
+        notify(ObjectCreatedEvent(comment))
         notify(ObjectAddedEvent(comment.__of__(self), self, id))
         notify(ContainerModifiedEvent(self))
 
diff --git a/plone/app/discussion/tests/test_comment.py b/plone/app/discussion/tests/test_comment.py
index cc115a1..52cc63b 100644
--- a/plone/app/discussion/tests/test_comment.py
+++ b/plone/app/discussion/tests/test_comment.py
@@ -9,6 +9,8 @@ from zope.component import createObject
 
 from zope.component import getMultiAdapter
 
+from Products.CMFCore.utils import getToolByName
+
 from Products.PloneTestCase.ptc import PloneTestCase
 
 from plone.app.discussion.tests.layer import DiscussionLayer
@@ -32,7 +34,10 @@ class CommentTest(PloneTestCase):
         self.portal.invokeFactory(id='doc1',
                           title='Document 1',
                           type_name='Document')
-
+        self.catalog = getToolByName(self.portal, 'portal_catalog')
+        self.document_brain = self.catalog.searchResults(
+            portal_type = 'Document')[0]
+    
     def test_factory(self):
         comment1 = createObject('plone.Comment')
         self.assert_(IComment.providedBy(comment1))
@@ -60,6 +65,35 @@ class CommentTest(PloneTestCase):
         self.assertEquals('123', comment1.getId())
         self.assertEquals(u'123', comment1.__name__)
 
+    def test_uid(self):
+        conversation = IConversation(self.portal.doc1)
+        comment1 = createObject('plone.Comment')
+        conversation.addComment(comment1)
+        comment_brain = self.catalog.searchResults(
+                            portal_type = 'Discussion Item')[0]
+        self.failUnless(comment_brain.UID)
+        
+    def test_uid_is_unique(self):
+        conversation = IConversation(self.portal.doc1)        
+        comment1 = createObject('plone.Comment')
+        conversation.addComment(comment1)
+        comment2 = createObject('plone.Comment')
+        conversation.addComment(comment2)
+        brains = self.catalog.searchResults(
+                     portal_type = 'Discussion Item')
+        self.assertNotEquals(brains[0].UID, None)
+        self.assertNotEquals(brains[1].UID, None)
+        self.assertNotEquals(brains[0].UID, brains[1].UID)
+    
+    def test_comment_uid_differs_from_content_uid(self):
+        conversation = IConversation(self.portal.doc1)        
+        comment1 = createObject('plone.Comment')
+        conversation.addComment(comment1)
+        comment_brain = self.catalog.searchResults(
+                            portal_type = 'Discussion Item')[0]
+        self.assertNotEquals(comment_brain.UID, None)
+        self.assertNotEquals(self.document_brain.UID, comment_brain.UID)
+
     def test_title(self):
         conversation = IConversation(self.portal.doc1)
         comment1 = createObject('plone.Comment')
diff --git a/setup.py b/setup.py
index e9278dc..4aa9b65 100644
--- a/setup.py
+++ b/setup.py
@@ -26,9 +26,11 @@ setup(name='plone.app.discussion',
           'collective.monkeypatcher',
           'plone.app.layout',
           'plone.app.registry',
+          'plone.app.uuid',          
           'plone.app.z3cform',
           'plone.indexer',
           'plone.registry',
+          'plone.uuid',
           'plone.z3cform',
           'ZODB3',
           'zope.interface',