diff --git a/pkgs/development/python-modules/skein/default.nix b/pkgs/development/python-modules/skein/default.nix
index e9016bb32ac7..42ead31640cf 100644
--- a/pkgs/development/python-modules/skein/default.nix
+++ b/pkgs/development/python-modules/skein/default.nix
@@ -19,7 +19,7 @@
 buildPythonPackage rec {
   pname = "skein";
   version = "0.8.2";
-  format = "setuptools";
+  pyproject = true;
   src = fetchPypi {
     inherit pname version;
     hash = "sha256-nXTqsJNX/LwAglPcPZkmdYPfF+vDLN+nNdZaDFTrHzE=";