diff --git a/tests/test_head_auto_apply.py b/tests/test_head_auto_apply.py
index 4e835aa..c289ca0 100644
--- a/tests/test_head_auto_apply.py
+++ b/tests/test_head_auto_apply.py
@@ -117,7 +117,11 @@ def test_sweep_skips_ungraduated_head(db_sync):
 
 @pytest.mark.asyncio
 async def test_auto_apply_disabled_blocks_real_run(client, db):
-    # head_auto_apply_enabled defaults False → a real sweep is refused (400).
+    # With the master switch OFF, a real sweep is refused (400). (It defaults ON
+    # now — opt-out — so the test disables it explicitly to exercise this path.)
+    s = (await db.execute(select(MLSettings).where(MLSettings.id == 1))).scalar_one()
+    s.head_auto_apply_enabled = False
+    await db.commit()
     resp = await client.post("/api/heads/auto-apply", json={"dry_run": False})
     assert resp.status_code == 400
     assert (await resp.get_json())["error"] == "auto_apply_disabled"