diff --git a/roles/horizon/vars/main.yml b/roles/horizon/vars/main.yml
index 7699b4a..b4c2130 100644
--- a/roles/horizon/vars/main.yml
+++ b/roles/horizon/vars/main.yml
@@ -31,7 +31,7 @@
             sso:
               enabled: true
               initial_choice: "{{ (keystone_domains is defined) | ternary(keystone_domains[0].name, 'atmosphere') }}"
-            idp_mapping: "{{ keystone_domains | default(horizon_keystone_domains) | vexxhost.atmosphere.keystone_domains_to_idp_mappings }}" # noqa: yaml[line-length]
+            idp_mapping: "{{ keystone_domains | default([{'name': 'atmosphere', 'label': 'Atmosphere'}]) | vexxhost.atmosphere.keystone_domains_to_idp_mappings }}" # noqa: yaml[line-length]
           raw:
             OPENSTACK_SSL_NO_VERIFY: "{{ ((cluster_issuer_type | default('self-signed')) == 'self-signed') | ternary('True', 'False') | string }}"
             WEBSSO_KEYSTONE_URL: https://{{ openstack_helm_endpoints['identity']['host_fqdn_override']['public']['host'] }}/v3