diff --git a/ceilometer/server/cluster.yml b/ceilometer/server/cluster.yml
index 19336b0..f965451 100644
--- a/ceilometer/server/cluster.yml
+++ b/ceilometer/server/cluster.yml
@@ -1,3 +1,4 @@
+# This class is deprecated since Openstack Pike
 classes:
 - service.ceilometer.server.cluster
 - service.haproxy.proxy.single