diff --git a/pkgs/development/ocaml-modules/kdf/default.nix b/pkgs/development/ocaml-modules/kdf/default.nix
index cb5c091e3d77..6f3f762e7049 100644
--- a/pkgs/development/ocaml-modules/kdf/default.nix
+++ b/pkgs/development/ocaml-modules/kdf/default.nix
@@ -8,12 +8,12 @@
   ohex,
 }:
 
-buildDunePackage rec {
+buildDunePackage (finalAttrs: {
   pname = "kdf";
   version = "1.0.0";
 
   src = fetchurl {
-    url = "https://github.com/robur-coop/kdf/releases/download/v${version}/kdf-${version}.tbz";
+    url = "https://github.com/robur-coop/kdf/releases/download/v${finalAttrs.version}/kdf-${finalAttrs.version}.tbz";
     hash = "sha256-0WFYKw7+ZtlY3WuMnCEGjp9kVM4hg3fWz4eCPexi4M4=";
   };
 
@@ -34,4 +34,4 @@ buildDunePackage rec {
     license = lib.licenses.bsd2;
     maintainers = [ lib.maintainers.vbgl ];
   };
-}
+})