diff --git a/faucet/fs/default.nix b/faucet/fs/default.nix
index fda65d1e..084e6177 100644
--- a/faucet/fs/default.nix
+++ b/faucet/fs/default.nix
@@ -25,7 +25,7 @@ in {
       enable = mkEnableOption "EFI system partition" // { default = true; };
       uuid = mkOption {
         type = with types; str;
-        default = "cafebabe";
+        default = "CAFE-BABE";
         description = "vfat serial number of EFI system partition";
       };
     };