diff --git a/pkgs/development/python-modules/zconfig/default.nix b/pkgs/development/python-modules/zconfig/default.nix
index bb739b974cca..83db908d50b0 100644
--- a/pkgs/development/python-modules/zconfig/default.nix
+++ b/pkgs/development/python-modules/zconfig/default.nix
@@ -23,6 +23,11 @@ buildPythonPackage rec {
 
   patches = lib.optional stdenv.hostPlatform.isMusl ./remove-setlocale-test.patch;
 
+  postPatch = ''
+    substituteInPlace pyproject.toml \
+      --replace-fail "setuptools >= 78.1.1,< 81" setuptools
+  '';
+
   build-system = [ setuptools ];
 
   buildInputs = [