diff --git a/tests/functional2/testlib/fixtures/nix.py b/tests/functional2/testlib/fixtures/nix.py
index e9285223d..6f7228f90 100644
--- a/tests/functional2/testlib/fixtures/nix.py
+++ b/tests/functional2/testlib/fixtures/nix.py
@@ -81,7 +81,7 @@ class NixSettings:
         (env.dirs.nix_conf_dir / "nix.conf").write_text(cfg)
         env.set_env("NIX_CONFIG", cfg)
         if self.nix_store_dir:
-            env.dirs.nix_store_dir = str(self.nix_store_dir)
+            env.dirs.nix_store_dir = self.nix_store_dir
 
 
 @dataclasses.dataclass
diff --git a/tests/functional2/testlib/fixtures/test_nix.py b/tests/functional2/testlib/fixtures/test_nix.py
index 4465d6fcc..16f2f602e 100644
--- a/tests/functional2/testlib/fixtures/test_nix.py
+++ b/tests/functional2/testlib/fixtures/test_nix.py
@@ -74,4 +74,4 @@ def test_nix_settings_to_env_overlay_store_dir(tmp_path: Path):
 
     settings.to_env_overlay(env)
     assert "store = " not in env._env["NIX_CONFIG"]
-    assert env.dirs.nix_store_dir == "/some/path"
+    assert str(env.dirs.nix_store_dir) == "/some/path"