diff --git a/site-cookbooks/remotestorage_discourse/recipes/nginx.rb b/site-cookbooks/remotestorage_discourse/recipes/nginx.rb
index ac3f842..450b877 100644
--- a/site-cookbooks/remotestorage_discourse/recipes/nginx.rb
+++ b/site-cookbooks/remotestorage_discourse/recipes/nginx.rb
@@ -18,6 +18,7 @@ end
 
 tls_cert_for domain do
   auth "gandi_dns"
+  acme_domain "letsencrypt.kosmos.org"
   action :create
 end