diff --git a/pkgs/development/python-modules/py-serializable/default.nix b/pkgs/development/python-modules/py-serializable/default.nix
index df2863e5b92b..3f342a1469ca 100644
--- a/pkgs/development/python-modules/py-serializable/default.nix
+++ b/pkgs/development/python-modules/py-serializable/default.nix
@@ -12,7 +12,7 @@
 buildPythonPackage rec {
   pname = "py-serializable";
   version = "0.17.1";
-  format = "pyproject";
+  pyproject = true;
 
   disabled = pythonOlder "3.7";