diff --git a/pkgs/development/ocaml-modules/duppy/default.nix b/pkgs/development/ocaml-modules/duppy/default.nix
index 6a2d79f49c7e..172f550008f8 100644
--- a/pkgs/development/ocaml-modules/duppy/default.nix
+++ b/pkgs/development/ocaml-modules/duppy/default.nix
@@ -5,7 +5,7 @@
   re,
 }:
 
-buildDunePackage rec {
+buildDunePackage (finalAttrs: {
   pname = "duppy";
   version = "0.9.5";
 
@@ -14,7 +14,7 @@ buildDunePackage rec {
   src = fetchFromGitHub {
     owner = "savonet";
     repo = "ocaml-duppy";
-    rev = "v${version}";
+    rev = "v${finalAttrs.version}";
     sha256 = "sha256-hWR7utYMxMjz8Cw0j6cgoHlUj4Jc7Q4vJHD5kGHN4Rc=";
   };
 
@@ -26,4 +26,4 @@ buildDunePackage rec {
     license = lib.licenses.lgpl21Only;
     maintainers = with lib.maintainers; [ dandellion ];
   };
-}
+})