diff --git a/testsite/group_vars/web.yml b/testsite/group_vars/web.yml
index fd828e2ff4c556adff580605d219469c5b6aa0ee..2cdfde5ee47a90c1b08fdcd0a5b72d5ba9777528 100644
--- a/testsite/group_vars/web.yml
+++ b/testsite/group_vars/web.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') }}"
 
 default_https_tls_key: "{{ lookup('file', inventory_dir + '/tls/web.' + testsite_domain + '_https.key') }}"
 default_https_tls_certificate: "{{ lookup('file', inventory_dir + '/tls/web.' + testsite_domain + '_https.pem') }}"