diff --git a/mastus/letsencrypt.nix b/mastus/letsencrypt.nix
index ee80a99..6567f3c 100644
--- a/mastus/letsencrypt.nix
+++ b/mastus/letsencrypt.nix
@@ -13,7 +13,7 @@
       mkdir -p /etc/sslcerts/acmeroot
       cd /etc/sslcerts
 
-      simp_le -d git.gebner.org -d mail.gebner.org --default_root $PWD/acmeroot -f fullchain.pem -f key.pem
+      simp_le -d git.gebner.org -d mail.gebner.org --default_root $PWD/acmeroot -f fullchain.pem -f key.pem --email gebner@gebner.org
     '';
 
     startAt = "04:00";