diff --git a/testsite/group_vars/backup.yml b/testsite/group_vars/backup.yml
index 2a279710eae0b379d600403feb104d5f343218a2..b122d7e5728ecb5ab1c0d281603e5a469f98171e 100644
--- a/testsite/group_vars/backup.yml
+++ b/testsite/group_vars/backup.yml
@@ -5,7 +5,7 @@ local_mail_aliases:
 
 smtp_relay_host: mail.{{ testsite_domain }}
 
-smtp_relay_truststore: /etc/ssl/certs/ca.pem
+smtp_relay_truststore:  "{{ lookup('file', inventory_dir + '/tls/ca.pem') }}"
 
 backup_clients:
   - server: web.{{ testsite_domain }}