diff --git a/nixbld-etc-nixos/configuration.nix b/nixbld-etc-nixos/configuration.nix
index 7665843c..5b38cde2 100644
--- a/nixbld-etc-nixos/configuration.nix
+++ b/nixbld-etc-nixos/configuration.nix
@@ -20,8 +20,8 @@ in
       ./afws-module.nix
       ./rt.nix
       (builtins.fetchTarball {
-        url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/70a970f5a02b7febec1c3065e10c4155b99ecf86/nixos-mailserver-nixos.tar.gz";
-        sha256 = "sha256:0samfdxzsg14bwjl50p5x92v9scpa6l8nxjlshrwhib03dai47n1";
+        url = "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/4966c0f63f04659015f064f2aa34b1893a16dfde/nixos-mailserver-nixos.tar.gz";
+        sha256 = "sha256:0bbv0hcwpm9vhvqnj51k84c3fx6x0vgv68yf0f8kdjvprpzxjdgk";
       })
     ];
 
@@ -931,7 +931,7 @@ in
     domains = [ "m-labs.hk" "m-labs.ph" ];
     enablePop3 = true;
     enablePop3Ssl = true;
-    certificateScheme = 3;
+    certificateScheme = "acme-nginx";
   } // (import /etc/nixos/secret/email_settings.nix);
   services.roundcube = {
     enable = true;