diff --git a/pkgs/development/ocaml-modules/piaf/default.nix b/pkgs/development/ocaml-modules/piaf/default.nix
index 7239a70a0b74..e148dbcc26b9 100644
--- a/pkgs/development/ocaml-modules/piaf/default.nix
+++ b/pkgs/development/ocaml-modules/piaf/default.nix
@@ -2,7 +2,7 @@
 , buildDunePackage
 , ocaml
 , dune-site
-, fetchzip
+, fetchurl
 , gluten-lwt-unix
 , lib
 , logs
@@ -22,9 +22,11 @@ buildDunePackage rec {
   pname = "piaf";
   version = "0.1.0";
 
-  src = fetchzip {
+  duneVersion = "3";
+
+  src = fetchurl {
     url = "https://github.com/anmonteiro/piaf/releases/download/${version}/piaf-${version}.tbz";
-    sha256 = "0d431kz3bkwlgdamvsv94mzd9631ppcjpv516ii91glzlfdzh5hz";
+    hash = "sha256-AMO+ptGox33Bi7u/H0SaeCU88XORrRU3UbLof3EwcmU=";
   };
 
   postPatch = ''