diff --git a/pkgs/development/python-modules/bencoder/default.nix b/pkgs/development/python-modules/bencoder/default.nix
index 195898ac5562..ea855b26ebfe 100644
--- a/pkgs/development/python-modules/bencoder/default.nix
+++ b/pkgs/development/python-modules/bencoder/default.nix
@@ -2,17 +2,20 @@
   lib,
   fetchPypi,
   buildPythonPackage,
+  setuptools,
 }:
 buildPythonPackage rec {
   pname = "bencoder";
   version = "0.2.0";
-  format = "setuptools";
+  pyproject = true;
 
   src = fetchPypi {
     inherit pname version;
     hash = "sha256-rENvM/3X51stkFdJHSq+77VjHvsTyBNAPbCtsRq1L8I=";
   };
 
+  build-system = [ setuptools ];
+
   pythonImportsCheck = [ "bencoder" ];
 
   # There are no tests.