diff --git a/pkgs/development/ocaml-modules/biniou/default.nix b/pkgs/development/ocaml-modules/biniou/default.nix
index 4dfc9496fb8a..6611099893e9 100644
--- a/pkgs/development/ocaml-modules/biniou/default.nix
+++ b/pkgs/development/ocaml-modules/biniou/default.nix
@@ -6,12 +6,12 @@
   easy-format,
 }:
 
-buildDunePackage rec {
+buildDunePackage (finalAttrs: {
   pname = "biniou";
   version = "1.2.2";
 
   src = fetchurl {
-    url = "https://github.com/ocaml-community/biniou/releases/download/${version}/biniou-${version}.tbz";
+    url = "https://github.com/ocaml-community/biniou/releases/download/${finalAttrs.version}/biniou-${finalAttrs.version}.tbz";
     hash = "sha256-i/P/F80Oyy1rbR2UywjvCJ1Eyu+W6brmvmg51Cj6MY8=";
   };
 
@@ -27,4 +27,4 @@ buildDunePackage rec {
     maintainers = [ lib.maintainers.vbgl ];
     mainProgram = "bdump";
   };
-}
+})