diff --git a/app/roles/openshift-installer/templates/install-config.yaml.j2 b/app/roles/openshift-installer/templates/install-config.yaml.j2
index 0f1d105..5d749cc 100644
--- a/app/roles/openshift-installer/templates/install-config.yaml.j2
+++ b/app/roles/openshift-installer/templates/install-config.yaml.j2
@@ -6,7 +6,7 @@ baseDomain: "{{ openshift_installer_base_domain }}"
   noProxy: "{{ ','.join(openshift_installer_proxy_noproxy) }}"
 {% endif %}{% if openshift_installer_proxy_ca | length > 0 %}
 additionalTrustBundle: |
-{{ openshift_installer_proxy_ca | indent(4, indentfirst=True) }}
+{{ openshift_installer_proxy_ca | indent(4, first=True) }}
 {% endif %}compute:
 - hyperthreading: Enabled
   name: worker