diff --git a/doc/man/man5/slapo-dds.5 b/doc/man/man5/slapo-dds.5
index e37df89d3a..875d50e723 100644
--- a/doc/man/man5/slapo-dds.5
+++ b/doc/man/man5/slapo-dds.5
@@ -53,7 +53,11 @@ overlay to the current database:
 .B overlay dds
 
 .LP
-The 
+The database must have a
+.B rootdn
+specified, otherwise, the
+.B dds
+overlay will not be able to delete expired objects. The 
 .B dds
 overlay may be used with any backend that implements the 
 .BR add ,