diff --git a/pkgs/development/python-modules/pysimplesoap/default.nix b/pkgs/development/python-modules/pysimplesoap/default.nix
index 80eb5b62070d..371def0d12de 100644
--- a/pkgs/development/python-modules/pysimplesoap/default.nix
+++ b/pkgs/development/python-modules/pysimplesoap/default.nix
@@ -4,13 +4,14 @@
   fetchPypi,
   buildPythonPackage,
   m2crypto,
+  setuptools,
   nix-update-script,
 }:
 
 buildPythonPackage rec {
   pname = "pysimplesoap";
   version = "1.16.2";
-  format = "setuptools";
+  pyproject = true;
 
   passthru.updateScript = nix-update-script { };
 
@@ -20,6 +21,8 @@ buildPythonPackage rec {
     hash = "sha256-sbv00NCt/5tlIZfWGqG3ZzGtYYhJ4n0o/lyyUJFtZ+E=";
   };
 
+  build-system = [ setuptools ];
+
   propagatedBuildInputs = [ m2crypto ];
 
   # Patches necessary for Python 3 compatibility plus bugfixes