diff --git a/tests/test_zero_touch_installer.py b/tests/test_zero_touch_installer.py
index a32795e..cc43373 100644
--- a/tests/test_zero_touch_installer.py
+++ b/tests/test_zero_touch_installer.py
@@ -22,6 +22,7 @@ ENROLL = {"agent_id": 7, "agent_token": "tok-never-in-env", "hub_url": "https://
 @pytest.fixture
 def world(tmp_path, monkeypatch):
     calls = []
+    monkeypatch.setenv("GTI_LOG_DIR", str(tmp_path / "logs"))  # never write the real ProgramData installer.log from tests
     monkeypatch.setenv("GTI_INSTALL_DIR", str(tmp_path / "inst"))
     monkeypatch.setattr(setup_main, "MEIPASS", tmp_path / "payload")
     payload = tmp_path / "payload"