diff --git a/pkgs/development/python-modules/bashlex/default.nix b/pkgs/development/python-modules/bashlex/default.nix
index fd319178e678..7086beb3092e 100644
--- a/pkgs/development/python-modules/bashlex/default.nix
+++ b/pkgs/development/python-modules/bashlex/default.nix
@@ -3,6 +3,7 @@
   buildPythonPackage,
   fetchFromGitHub,
   python,
+  setuptools,
   pytestCheckHook,
 }:
 
@@ -10,7 +11,7 @@ buildPythonPackage rec {
   pname = "bashlex";
   version = "0.18";
 
-  format = "setuptools";
+  pyproject = true;
 
   src = fetchFromGitHub {
     owner = "idank";
@@ -19,6 +20,8 @@ buildPythonPackage rec {
     hash = "sha256-ddZN91H95RiTLXx4lpES1Dmz7nNsSVUeuFuOEpJ7LQI=";
   };
 
+  build-system = [ setuptools ];
+
   # workaround https://github.com/idank/bashlex/issues/51
   preBuild = ''
     ${python.pythonOnBuildForHost.interpreter} -c 'import bashlex'