diff --git a/plone/app/discussion/KNOWN_ISSUES.txt b/plone/app/discussion/KNOWN_ISSUES.txt
index 53759af..bb4cbe8 100644
--- a/plone/app/discussion/KNOWN_ISSUES.txt
+++ b/plone/app/discussion/KNOWN_ISSUES.txt
@@ -2,4 +2,6 @@
 KNOWN ISSUES
 ============
 
-- Clear and rebuild the catalog looses all the comments.
\ No newline at end of file
+- Clear and rebuild the catalog looses all the comments.
+
+- Comment objects are not indexed with Plone 4 (Plone 3.3 works fine).
\ No newline at end of file