diff --git a/pkgs/development/python-modules/pytest-sugar/default.nix b/pkgs/development/python-modules/pytest-sugar/default.nix
index 3c89086a1db4..d5d761cf6418 100644
--- a/pkgs/development/python-modules/pytest-sugar/default.nix
+++ b/pkgs/development/python-modules/pytest-sugar/default.nix
@@ -17,6 +17,12 @@ buildPythonPackage rec {
     hash = "sha256-c7i2UWPr8Q+fZx76ue7T1W8g0spovag/pkdAqSwI9l0=";
   };
 
+  postPatch = ''
+    # pytest 9 compat
+    substituteInPlace test_sugar.py \
+      --replace-fail "startdir" "start_path"
+  '';
+
   build-system = [
     setuptools
   ];