diff --git a/pkgs/development/ocaml-modules/mirage-clock/default.nix b/pkgs/development/ocaml-modules/mirage-clock/default.nix
index 2cf12cec92ec..c6e86600620c 100644
--- a/pkgs/development/ocaml-modules/mirage-clock/default.nix
+++ b/pkgs/development/ocaml-modules/mirage-clock/default.nix
@@ -4,14 +4,14 @@
   fetchurl,
 }:
 
-buildDunePackage rec {
+buildDunePackage (finalAttrs: {
   pname = "mirage-clock";
   version = "4.2.0";
 
   minimalOCamlVersion = "4.06";
 
   src = fetchurl {
-    url = "https://github.com/mirage/mirage-clock/releases/download/v${version}/mirage-clock-${version}.tbz";
+    url = "https://github.com/mirage/mirage-clock/releases/download/v${finalAttrs.version}/mirage-clock-${finalAttrs.version}.tbz";
     hash = "sha256-+hfRXVviPHm6dB9ffLiO1xEt4WpEEM6oHHG5gIaImEc=";
   };
 
@@ -21,4 +21,4 @@ buildDunePackage rec {
     license = lib.licenses.isc;
     maintainers = [ lib.maintainers.vbgl ];
   };
-}
+})