diff --git a/tests/test_windows_subprocess_no_window_flags.py b/tests/test_windows_subprocess_no_window_flags.py
index 21c563646f..d1e49a4909 100644
--- a/tests/test_windows_subprocess_no_window_flags.py
+++ b/tests/test_windows_subprocess_no_window_flags.py
@@ -78,12 +78,19 @@ def test_bounded_git_probe_fast_path_spawn_contract_windows(monkeypatch):
     helper caches from the real platform at import. ``windows_hide_flags`` is
     still stubbed so the expected value is a fixed constant rather than
     whatever bundle the helper currently returns.
+
+    The seam is the Job-Object container (``local_runtime.processes.spawn_server``),
+    which is what the probe hands its spawn contract to on Windows; the container
+    itself adds CREATE_SUSPENDED and assigns the real process handle, which a fake
+    Popen cannot provide.
     """
     from hermes_cli import _subprocess_compat
+    from hermes_cli.local_runtime import processes
 
     spawns = []
+    fake_popen = _make_fake_popen(spawns, stdout="main\n")
     monkeypatch.setattr(_subprocess_compat, "windows_hide_flags", lambda: _CREATE_NO_WINDOW)
-    monkeypatch.setattr(_subprocess_compat.subprocess, "Popen", _make_fake_popen(spawns, stdout="main\n"))
+    monkeypatch.setattr(processes, "spawn_server", lambda cmd, **kw: (fake_popen(cmd, **kw), None))
 
     out = _subprocess_compat.bounded_git_probe(
         ["git", "-C", "C:/repo", "branch", "--show-current"], timeout=1.5