diff --git a/pkgs/development/python-modules/bjoern/default.nix b/pkgs/development/python-modules/bjoern/default.nix
index ae4de2f37c9c..f6fb503578e9 100644
--- a/pkgs/development/python-modules/bjoern/default.nix
+++ b/pkgs/development/python-modules/bjoern/default.nix
@@ -4,12 +4,13 @@
   fetchFromGitHub,
   libev,
   python,
+  setuptools,
 }:
 
 buildPythonPackage rec {
   pname = "bjoern";
   version = "3.2.2";
-  format = "setuptools";
+  pyproject = true;
 
   src = fetchFromGitHub {
     owner = "jonashaag";
@@ -19,6 +20,8 @@ buildPythonPackage rec {
     fetchSubmodules = true; # fetch http-parser and statsd-c-client submodules
   };
 
+  build-system = [ setuptools ];
+
   buildInputs = [ libev ];
 
   checkPhase = ''