diff --git a/CHANGES.txt b/CHANGES.txt
index 9f427ad..885b89f 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,6 +1,12 @@
 Changelog
 =========
 
+1.0b6 (unreleased)
+------------------
+
+* Catch Type errors in indexers if object can not be adapted to IDiscussion
+  [do3cc]
+
 1.0b5 (2010-07-16)
 ------------------
 
diff --git a/plone/app/discussion/catalog.py b/plone/app/discussion/catalog.py
index c134ef4..062e91d 100644
--- a/plone/app/discussion/catalog.py
+++ b/plone/app/discussion/catalog.py
@@ -25,25 +25,39 @@ def total_comments(object):
     # Total number of comments on a conversation
     # Indexers won't work on old discussion items
     if object.meta_type != 'Discussion Item':
-
-        conversation = IConversation(object)
-        return conversation.total_comments
+        try:
+            conversation = IConversation(object)
+            return conversation.total_comments
+        except TypeError:
+            # The item is contentish but nobody
+            # implemented an adapter for it
+            pass
 
 @indexer(IContentish, IZCatalog)
 def last_comment_date(object):
     # Date of the latest comment on a conversation
     # Indexers won't work on old discussion items
     if object.meta_type != 'Discussion Item':
-        conversation = IConversation(object)
-        return conversation.last_comment_date
+        try:
+            conversation = IConversation(object)
+            return conversation.last_comment_date
+        except TypeError:
+            # The item is contentish but nobody
+            # implemented an adapter for it
+            pass
 
 @indexer(IContentish, IZCatalog)
 def commentators(object):
     # List of commentators on a conversation
     # Indexers won't work on old discussion items
     if object.meta_type != 'Discussion Item':
-        conversation = IConversation(object)
-        return tuple(conversation.commentators.keys())
+        try:
+            conversation = IConversation(object)
+            return tuple(conversation.commentators.keys())
+        except TypeError:
+            # The item is contentish but nobody
+            # implemented an adapter for it
+            pass
 
 # Comment Indexers