diff --git a/clusters/fixed-3-cephfs.yaml b/clusters/fixed-3-cephfs.yaml
index 4191540ee5f..74a24a3e9d6 100644
--- a/clusters/fixed-3-cephfs.yaml
+++ b/clusters/fixed-3-cephfs.yaml
@@ -1,4 +1,4 @@
 roles:
 - [mon.a, mds.a, osd.0, osd.1]
-- [mon.b, mon.c, osd.2, osd.3]
+- [mon.b, mds.a-s, mon.c, osd.2, osd.3]
 - [client.0]