diff --git a/mail-server/systemd.nix b/mail-server/systemd.nix
index a5da59d..0c82b16 100644
--- a/mail-server/systemd.nix
+++ b/mail-server/systemd.nix
@@ -77,11 +77,12 @@ in
 
     # Create dkim certificates
     systemd.services.rmilter = {
+      requires = [ "rmilter.socket" ];
+      after = [ "rmilter.socket" ];
       preStart =
       ''
         ${create_dkim_cert}
       '';
     };
-
   };
 }