diff --git a/ansible/roles/prometheus/templates/clouds.yml.j2 b/ansible/roles/prometheus/templates/clouds.yml.j2
index 105178ba58..bbbf44b5e9 100644
--- a/ansible/roles/prometheus/templates/clouds.yml.j2
+++ b/ansible/roles/prometheus/templates/clouds.yml.j2
@@ -10,3 +10,4 @@ clouds:
      project_domain_name: 'Default'
      user_domain_name: 'Default'
      auth_url: {{ admin_protocol }}://{{ kolla_internal_fqdn | put_address_in_context('url') }}:{{ keystone_admin_port }}/v3
+     cacert: {{ openstack_cacert }}
diff --git a/releasenotes/notes/bug-1850812-e840453d44e17d34.yaml b/releasenotes/notes/bug-1850812-e840453d44e17d34.yaml
new file mode 100644
index 0000000000..56c95b887b
--- /dev/null
+++ b/releasenotes/notes/bug-1850812-e840453d44e17d34.yaml
@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    Fix prometheus-openstack-exporter to use CA certificate.