diff --git a/roles/ceph-common/templates/ceph.conf.j2 b/roles/ceph-common/templates/ceph.conf.j2
index 6503d5eea..75132fe4d 100644
--- a/roles/ceph-common/templates/ceph.conf.j2
+++ b/roles/ceph-common/templates/ceph.conf.j2
@@ -5,8 +5,8 @@
   auth cluster required = cephx
   auth service required = cephx
   auth client required = cephx
-  cephx require signatures = {{ cephx_require_signatures }}
-  cephx cluster require signatures = {{ cephx_require_signatures }}
+  cephx require signatures = {{ cephx_require_signatures }} # Kernel RBD does NOT support signatures!
+  cephx cluster require signatures = {{ cephx_cluster_require_signatures }}
   cephx service require signatures = {{ cephx_service_require_signatures }}
 {% else %}
   auth cluster required = none
diff --git a/roles/ceph-common/vars/main.yml b/roles/ceph-common/vars/main.yml
index a27f63e86..09064dd0c 100644
--- a/roles/ceph-common/vars/main.yml
+++ b/roles/ceph-common/vars/main.yml
@@ -26,7 +26,7 @@ ceph_dev_redhat_distro: centos7
 ## Ceph options
 #
 cephx: true
-cephx_require_signatures: true
+cephx_require_signatures: true # Kernel RBD does NOT support signatures!
 cephx_cluster_require_signatures: true
 cephx_service_require_signatures: false
 disable_in_memory_logs: true