diff --git a/plone/app/discussion/browser/moderation.pt b/plone/app/discussion/browser/moderation.pt
index 60f4df0..2fe71ad 100644
--- a/plone/app/discussion/browser/moderation.pt
+++ b/plone/app/discussion/browser/moderation.pt
@@ -116,7 +116,7 @@
                                 <td tal:content="python:toLocalizedTime(item.ModificationDate, long_format=1)" />
                                 <td>
                                     <a tal:attributes="href item/getURL"
-                                       tal:content="item/@@plone_context_state/parent|nothing" />
+                                       tal:content="item/in_response_to" />
                                 </td>
                                 <td>
                                     <a tal:attributes="href item/getURL"
diff --git a/plone/app/discussion/catalog.py b/plone/app/discussion/catalog.py
index 20310ea..9f69ae0 100644
--- a/plone/app/discussion/catalog.py
+++ b/plone/app/discussion/catalog.py
@@ -60,6 +60,10 @@ def description(object):
 def searchable_text(object):
     return object.title, object.text
 
+@indexer(IComment)
+def in_response_to(object):
+    return object.__parent__.__parent__.title_or_id()
+
 @indexer(IComment)
 def effective(object):
     # the catalog index needs Zope DateTime instead of Python datetime
diff --git a/plone/app/discussion/configure.zcml b/plone/app/discussion/configure.zcml
index 1b3a1fd..10bf672 100644
--- a/plone/app/discussion/configure.zcml
+++ b/plone/app/discussion/configure.zcml
@@ -63,6 +63,7 @@
     <adapter name="total_comments" factory=".catalog.total_comments" />
     <adapter name="last_comment_date" factory=".catalog.last_comment_date" />
     <adapter name="commentators" factory=".catalog.commentators" />
+    <adapter name="in_response_to" factory=".catalog.in_response_to" />
 
     <!-- comment indexes -->
     <adapter name="Title" factory=".catalog.title" />
diff --git a/plone/app/discussion/profiles/default/catalog.xml b/plone/app/discussion/profiles/default/catalog.xml
index 1737dda..51428c5 100644
--- a/plone/app/discussion/profiles/default/catalog.xml
+++ b/plone/app/discussion/profiles/default/catalog.xml
@@ -12,5 +12,6 @@
     <column value="total_comments" />
 	<column value="last_comment_date" />
 	<column value="commentators" />
+    <column value="in_response_to" />
 
 </object>
diff --git a/plone/app/discussion/tests/test_catalog.py b/plone/app/discussion/tests/test_catalog.py
index dee593b..131a044 100644
--- a/plone/app/discussion/tests/test_catalog.py
+++ b/plone/app/discussion/tests/test_catalog.py
@@ -22,6 +22,7 @@ class CatalogSetupTest(PloneTestCase):
         self.failUnless('total_comments' in self.portal.portal_catalog.indexes())
         self.failUnless('commentators' in self.portal.portal_catalog.indexes())
         self.failUnless('total_comments' in self.portal.portal_catalog.schema())
+        self.failUnless('in_response_to' in self.portal.portal_catalog.schema())
 
     def test_collection_criteria_installed(self):
         try:
@@ -212,5 +213,10 @@ class CommentCatalogTest(PloneTestCase):
     def test_creator(self):
         self.assertEquals(self.comment_brain.Creator, 'Jim')
 
+    def test_in_response_to(self):
+        # make sure in_response_to returns the title or id of the content
+        # object the comment was added to
+        self.assertEquals(self.comment_brain.in_response_to, 'doc1')
+
 def test_suite():
     return unittest.defaultTestLoader.loadTestsFromName(__name__)
\ No newline at end of file
diff --git a/plone/app/discussion/tests/test_indexers.py b/plone/app/discussion/tests/test_indexers.py
index 156f39f..4cf09d4 100644
--- a/plone/app/discussion/tests/test_indexers.py
+++ b/plone/app/discussion/tests/test_indexers.py
@@ -144,14 +144,12 @@ class CommentIndexersTest(PloneTestCase):
     def test_creator(self):
         self.assertEquals(catalog.creator(self.comment)(), ('Jim'))
 
-    def test_in_reply_to(self):
-        pass
-
-    def test_review_state(self):
-        pass
-
-    def test_object_provides(self):
-        pass
+    def test_in_response_to(self):
+        # make sure in_response_to returns the title or id of the content
+        # object the comment was added to
+        self.assertEquals(catalog.in_response_to(self.comment)(), 'doc1')
+        self.portal.doc1.title = 'Document 1'
+        self.assertEquals(catalog.in_response_to(self.comment)(), 'Document 1')
 
 def test_suite():
     return unittest.defaultTestLoader.loadTestsFromName(__name__)
\ No newline at end of file