diff --git a/doc/man/man5/slapo-unique.5 b/doc/man/man5/slapo-unique.5
index 720c35a4ed..3ceef5ea9d 100644
--- a/doc/man/man5/slapo-unique.5
+++ b/doc/man/man5/slapo-unique.5
@@ -54,7 +54,8 @@ Keywords
 .BR ignore ,
 and
 .B serialize
-have to be enclosed in quotes (") together with the URI.
+have to be enclosed in quotes (") together with the URI when using
+deprecated slapd.conf configurations.
 
 The LDAP URI syntax is a subset of
 .B RFC-4516,