diff --git a/roles/dns/master/templates/zone.db b/roles/dns/master/templates/zone.db
index f4acf27..dcf0110 100644
--- a/roles/dns/master/templates/zone.db
+++ b/roles/dns/master/templates/zone.db
@@ -11,4 +11,7 @@ $TTL 86400
 $INCLUDE {{ key.path }}
 {% endfor %}
 
+; Certification Authority Authorization
+@ IN CAA 0 issue "letsencrypt.org"
+
 {{ entries }}