diff --git a/nix/packages/by-name/hrt-time/package.nix b/nix/packages/by-name/hrt-time/package.nix
index 29a50de3..cf76163b 100644
--- a/nix/packages/by-name/hrt-time/package.nix
+++ b/nix/packages/by-name/hrt-time/package.nix
@@ -3,17 +3,14 @@
   stdenvNoCC,
   lib,
 }:
-let
-  rev = "b344ab770e4c08d0bb13c38ea61979b282e24db7";
-in
-stdenvNoCC.mkDerivation {
+stdenvNoCC.mkDerivation (finalAttrs: {
   pname = "hrt-time";
-  version = "unstable-" + lib.substring 0 8 rev;
+  version = "unstable-" + lib.substring 0 8 finalAttrs.src.rev;
 
   src = fetchFromGitHub {
     owner = "ariannelafraise";
     repo = "hrt-time";
-    inherit rev;
+    rev = "b344ab770e4c08d0bb13c38ea61979b282e24db7";
     hash = "sha256-+AhLkcCETVnF6S+ov1oKxhs3M9F6ghyyERoLN3aMMxw=";
   };
 
@@ -31,4 +28,4 @@ stdenvNoCC.mkDerivation {
   ];
 
   meta.mainProgram = "hrt-time";
-}
+})