diff --git a/pkgs/development/ocaml-modules/fiber/default.nix b/pkgs/development/ocaml-modules/fiber/default.nix
index 37e008884d1d..fc9eafe6d088 100644
--- a/pkgs/development/ocaml-modules/fiber/default.nix
+++ b/pkgs/development/ocaml-modules/fiber/default.nix
@@ -7,12 +7,12 @@
   stdune,
 }:
 
-buildDunePackage rec {
+buildDunePackage (finalAttrs: {
   pname = "fiber";
   version = "3.7.0";
 
   src = fetchurl {
-    url = "https://github.com/ocaml-dune/fiber/releases/download/${version}/fiber-lwt-${version}.tbz";
+    url = "https://github.com/ocaml-dune/fiber/releases/download/${finalAttrs.version}/fiber-lwt-${finalAttrs.version}.tbz";
     hash = "sha256-hkihWuk/5pQpmc42iHQpo5E7YoKcRxTlIMwOehw7loI=";
   };
 
@@ -33,4 +33,4 @@ buildDunePackage rec {
     maintainers = [ ];
     license = lib.licenses.mit;
   };
-}
+})