diff --git a/pkgs/development/python-modules/cronsim/default.nix b/pkgs/development/python-modules/cronsim/default.nix
index d63b04f84d52..6793c4772a08 100644
--- a/pkgs/development/python-modules/cronsim/default.nix
+++ b/pkgs/development/python-modules/cronsim/default.nix
@@ -2,24 +2,24 @@
   lib,
   buildPythonPackage,
   fetchFromGitHub,
+  setuptools,
   pytestCheckHook,
-  pythonOlder,
 }:
 
 buildPythonPackage rec {
   pname = "cronsim";
-  version = "2.6";
-  format = "setuptools";
-
-  disabled = pythonOlder "3.7";
+  version = "2.7";
+  pyproject = true;
 
   src = fetchFromGitHub {
     owner = "cuu508";
     repo = "cronsim";
     tag = version;
-    hash = "sha256-WJ3v2cqAKZkXp1u8xJ0aFuyHPq0gn24DRxpnq5cH/90=";
+    hash = "sha256-9TextQcZAX5Ri6cc+Qd4T+u8XjxriqoTsy/9/G8XDAM=";
   };
 
+  build-system = [ setuptools ];
+
   nativeCheckInputs = [ pytestCheckHook ];
 
   pythonImportsCheck = [ "cronsim" ];