diff --git a/packages/proton-cachyos/default.nix b/packages/proton-cachyos/default.nix
index 81bad64..a86e7e4 100644
--- a/packages/proton-cachyos/default.nix
+++ b/packages/proton-cachyos/default.nix
@@ -8,9 +8,8 @@
   owner ? "CachyOS",
   repo ? "proton-cachyos",
   # Variant selection (null -> use defaultVariant from version.json)
-  variant ? null,
+  variant ? "cachyos-v4",
   # Packaging/customization knobs
-  toolTitle ? null,
   toolPattern ? "proton-.*",
   tarballPrefix ? "proton-",
   tarballSuffix ? "-x86_64_v4.tar.xz",
@@ -27,6 +26,8 @@ let
   base = vars.base;
   release = vars.release;
 
+  toolTitle = "proton-${variant}-latest";
+
   # Derived values for the current variant
   releaseVersion = "${releasePrefix}${base}-${release}${releaseSuffix}";
   homepage = "https://github.com/${owner}/${repo}";