diff --git a/pkgs/development/python-modules/ci-py/default.nix b/pkgs/development/python-modules/ci-py/default.nix
index b516b3624a9e..66c2d4a8a257 100644
--- a/pkgs/development/python-modules/ci-py/default.nix
+++ b/pkgs/development/python-modules/ci-py/default.nix
@@ -2,22 +2,27 @@
   lib,
   buildPythonPackage,
   fetchPypi,
+  setuptools,
   pytestCheckHook,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "ci-py";
   version = "1.0.0";
-  format = "setuptools";
+  pyproject = true;
+
+  __structuredAttrs = true;
 
   src = fetchPypi {
-    inherit pname version;
+    inherit (finalAttrs) pname version;
     hash = "sha256-R/6bLsXOKGxiJDZUvvOuvLp3usEhfg698qvvgOwBXYk=";
   };
 
+  build-system = [ setuptools ];
+
   postPatch = ''
     substituteInPlace setup.py \
-      --replace "'pytest-runner', " ""
+      --replace-fail "'pytest-runner', " ""
   '';
 
   nativeCheckInputs = [ pytestCheckHook ];
@@ -31,4 +36,4 @@ buildPythonPackage rec {
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [ bcdarwin ];
   };
-}
+})