diff --git a/pkgs/development/ocaml-modules/base64/default.nix b/pkgs/development/ocaml-modules/base64/default.nix
index b2e3e0c5e74d..de0bc13e2833 100644
--- a/pkgs/development/ocaml-modules/base64/default.nix
+++ b/pkgs/development/ocaml-modules/base64/default.nix
@@ -1,25 +1,17 @@
-{ lib, fetchpatch, fetchzip, buildDunePackage, alcotest, bos }:
-
-let version = "3.2.0"; in
+{ lib, fetchurl, buildDunePackage, alcotest, bos, dune-configurator }:
 
 buildDunePackage rec {
   pname = "base64";
-  inherit version;
+  version = "3.4.0";
 
-  src = fetchzip {
-    url = "https://github.com/mirage/ocaml-base64/archive/v${version}.tar.gz";
-    sha256 = "1ilw3zj0w6cq7i4pvr8m2kv5l5f2y9aldmv72drlwwns013b1gwy";
+  useDune2 = true;
+
+  src = fetchurl {
+    url = "https://github.com/mirage/ocaml-base64/releases/download/v${version}/base64-v${version}.tbz";
+    sha256 = "0d0n5gd4nkdsz14jnxq13f1f7rzxmndg5xql039a8wfppmazd70w";
   };
 
-  minimumOCamlVersion = "4.03";
-
-  buildInputs = [ bos ];
-
-  # Fix test-suite for alcotest ≥ 1.0
-  patches = [(fetchpatch {
-    url = "https://github.com/mirage/ocaml-base64/commit/8d334d02aa52875158fae3e2fb8fe0a5596598d0.patch";
-    sha256 = "0lvqdp98qavpzis1wgwh3ijajq79hq47898gsrk37fpyjbrdzf5q";
-  })];
+  buildInputs = [ bos dune-configurator ];
 
   doCheck = true;
   checkInputs = [ alcotest ];