diff --git a/pkgs/development/python-modules/pyscss/default.nix b/pkgs/development/python-modules/pyscss/default.nix
index 26e9bdec6d3f..278aa7b1c247 100644
--- a/pkgs/development/python-modules/pyscss/default.nix
+++ b/pkgs/development/python-modules/pyscss/default.nix
@@ -3,13 +3,14 @@
   buildPythonPackage,
   fetchFromGitHub,
   pytestCheckHook,
+  setuptools,
   six,
 }:
 
 buildPythonPackage (finalAttrs: {
   pname = "pyscss";
   version = "1.4.0";
-  format = "setuptools";
+  pyproject = true;
 
   __structuredAttrs = true;
 
@@ -20,9 +21,11 @@ buildPythonPackage (finalAttrs: {
     hash = "sha256-z0y4z+/JE6rZWHAvps/taDZvutyVhxxs2gMujV5rNu4=";
   };
 
-  nativeCheckInputs = [ pytestCheckHook ];
+  build-system = [ setuptools ];
 
-  propagatedBuildInputs = [ six ];
+  dependencies = [ six ];
+
+  nativeCheckInputs = [ pytestCheckHook ];
 
   # Test suite is broken.
   # See https://github.com/Kronuz/pyScss/issues/415