diff --git a/data/authelia/config/configuration.yml b/data/authelia/config/configuration.yml
index b858a00..c691c2e 100644
--- a/data/authelia/config/configuration.yml
+++ b/data/authelia/config/configuration.yml
@@ -840,7 +840,7 @@ session:
       ##   - The above 'domain' option MUST either:
       ##      - Match the host portion of this URI.
       ##      - Match the suffix of the host portion when prefixed with '.'.
-      authelia_url: 'https://auth.{{ env "TEMPLATE_DOMAIN" }}'
+      authelia_url: 'https://{{ env "TEMPLATE_AUTHELIA_SUBDOMAIN" }}.{{ env "TEMPLATE_DOMAIN" }}'
 
       ## Optional. The fully qualified URI used as the redirection location if the portal is accessed directly. Not
       ## configuring this option disables the automatic redirection behaviour.