diff --git a/modules/mail/default.nix b/modules/mail/default.nix
index d9538f8..6b81a36 100644
--- a/modules/mail/default.nix
+++ b/modules/mail/default.nix
@@ -47,5 +47,7 @@ in {
 
       hashedPasswordFile = config.secrets.mailPassword.path;
     };
+
+    stateVersion = 2;
   };
 }