diff --git a/hieradata/roles/infra/ceph/rgw.yaml b/hieradata/roles/infra/ceph/rgw.yaml
index 7b65271..75163f1 100644
--- a/hieradata/roles/infra/ceph/rgw.yaml
+++ b/hieradata/roles/infra/ceph/rgw.yaml
@@ -14,6 +14,9 @@ profiles::pki::vault::alt_names:
   - radosgw.service.consul
   - radosgw.query.consul
   - "radosgw.service.%{facts.country}-%{facts.region}.consul"
+  # S3 endpoint name (s3.ceph.unkin.net CNAME -> radosgw.service.consul); needed
+  # on the cert so TLS validates for that hostname.
+  - s3.ceph.unkin.net
 
 # additional repos
 profiles::yum::global::repos:
@@ -26,6 +29,8 @@ profiles::yum::global::repos:
 profiles::nginx::simpleproxy::nginx_vhost: 'radosgw.service.consul'
 profiles::nginx::simpleproxy::nginx_aliases:
   - radosgw.service.au-syd1.consul
+  # nginx (443 -> radosgw:7480) must answer for the S3 endpoint name too.
+  - s3.ceph.unkin.net
 profiles::nginx::simpleproxy::proxy_port: 7480
 profiles::nginx::simpleproxy::proxy_path: '/'
 nginx::client_max_body_size: 5000M