diff --git a/config/hosts/mail-1/simple-nixos-mailserver.nix b/config/hosts/mail-1/simple-nixos-mailserver.nix
index c08a1a3..0f8d76f 100644
--- a/config/hosts/mail-1/simple-nixos-mailserver.nix
+++ b/config/hosts/mail-1/simple-nixos-mailserver.nix
@@ -4,6 +4,7 @@
     simple-nixos-mailserver.nixosModule {
       mailserver = {
         enable = true;
+        stateVersion = 1;
         openFirewall = true;
         fqdn = "mail-1.grzb.de";
         enableImap = false;