diff --git a/pkgs/development/python-modules/expiringdict/default.nix b/pkgs/development/python-modules/expiringdict/default.nix
index 4fc3366a7a42..e4904230a497 100644
--- a/pkgs/development/python-modules/expiringdict/default.nix
+++ b/pkgs/development/python-modules/expiringdict/default.nix
@@ -6,12 +6,13 @@
   dill,
   mock,
   pytestCheckHook,
+  setuptools
 }:
 
 buildPythonPackage rec {
   pname = "expiringdict";
   version = "1.2.2";
-  format = "setuptools";
+  pyproject = true;
 
   # use fetchFromGitHub instead of fetchPypi because the test suite of
   # the package is not included into the PyPI tarball
@@ -36,6 +37,8 @@ buildPythonPackage rec {
     })
   ];
 
+  build-system = [ setuptools ];
+
   nativeCheckInputs = [
     dill
     mock