diff --git a/pkgs/development/ocaml-modules/hex/default.nix b/pkgs/development/ocaml-modules/hex/default.nix
index 8e9dd2db25008..526989734abdc 100644
--- a/pkgs/development/ocaml-modules/hex/default.nix
+++ b/pkgs/development/ocaml-modules/hex/default.nix
@@ -1,17 +1,19 @@
-{ stdenv, fetchurl, buildDunePackage, cstruct }:
+{ stdenv, fetchurl, buildDunePackage, bigarray-compat, cstruct }:
 
 buildDunePackage rec {
   pname = "hex";
-  version = "1.3.0";
+  version = "1.4.0";
+
+  useDune2 = true;
 
   minimumOCamlVersion = "4.02";
 
   src = fetchurl {
     url = "https://github.com/mirage/ocaml-${pname}/releases/download/v${version}/hex-v${version}.tbz";
-    sha256 = "193567pn58df3b824vmfanncdfgf9cxzl7q3rq39zl9szvzhvkja";
+    sha256 = "07b9y0lmnflsslkrm6xilkj40n8sf2hjqkyqghnk7sw5l0plkqsp";
   };
 
-  propagatedBuildInputs = [ cstruct ];
+  propagatedBuildInputs = [ bigarray-compat cstruct ];
   doCheck = true;
 
   meta = {