diff --git a/bundles/letsencrypt/files/domains.txt b/bundles/letsencrypt/files/domains.txt
index 6895b83..533cdf2 100644
--- a/bundles/letsencrypt/files/domains.txt
+++ b/bundles/letsencrypt/files/domains.txt
@@ -1,5 +1,5 @@
 ${node.hostname}
 
-% for domain, aliases in node.metadata.get('letsencrypt', {}).get('domains', {}).items():
-${domain} ${' '.join(aliases)}
+% for domain, aliases in sorted(node.metadata.get('letsencrypt', {}).get('domains', {}).items()):
+${domain} ${' '.join(sorted(aliases))}
 % endfor