diff --git a/library/roles/postfix/templates/main.cf.j2 b/library/roles/postfix/templates/main.cf.j2
index 8d177203..270199e9 100644
--- a/library/roles/postfix/templates/main.cf.j2
+++ b/library/roles/postfix/templates/main.cf.j2
@@ -755,7 +755,7 @@ readme_directory = no
 # TLS parameters
 {% if letsencrypt_acme_install is defined %}
 {% if postfix_use_letsencrypt %}
-smtpd_tls_cert_file={{ letsencrypt_acme_certs_dir }}/cert
+smtpd_tls_cert_file={{ letsencrypt_acme_certs_dir }}/fullchain
 smtpd_tls_key_file={{ letsencrypt_acme_certs_dir }}/privkey
 {% else %}
 smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem