diff --git a/default.nix b/default.nix
index 5e54952..70db29f 100644
--- a/default.nix
+++ b/default.nix
@@ -1601,5 +1601,9 @@ in
       [ "mailserver" "dkim" "defaults" "selector" ]
     )
     (mkRenamedOptionModule [ "mailserver" "dkimKeyType" ] [ "mailserver" "dkim" "defaults" "keyType" ])
+    (mkRenamedOptionModule
+      [ "mailserver" "dkimKeyBits" ]
+      [ "mailserver" "dkim" "defaults" "keyLength" ]
+    )
   ];
 }