diff --git a/tests/test_store_and_config.py b/tests/test_store_and_config.py
new file mode 100644
index 0000000..0e3ae5c
--- /dev/null
+++ b/tests/test_store_and_config.py
@@ -0,0 +1,32 @@
+from uuid import uuid4
+
+import pytest
+from pydantic import ValidationError
+
+from app.config import Settings
+from app.models import MonitorCreate, MonitorState, StatusSnapshot
+from app.store import MonitorStore
+
+pytestmark = pytest.mark.anyio
+
+
+async def test_revision_prevents_stale_check_write() -> None:
+    store = MonitorStore()
+    monitor = await store.create(MonitorCreate(name="a", url="https://example.com"))
+    pending = await store.begin_check(monitor.id)
+    assert pending is not None
+    _, revision = pending
+    await store.update(monitor.id, MonitorCreate(name="b", url="https://example.org"))
+    saved = await store.finish_check(
+        monitor.id, revision, StatusSnapshot(state=MonitorState.UP),
+    )
+    assert saved is False
+    assert (await store.get(monitor.id)).status.state is MonitorState.UNKNOWN  # type: ignore[union-attr]
+    assert await store.begin_check(uuid4()) is None
+
+
+async def test_settings_validation() -> None:
+    with pytest.raises(ValidationError):
+        Settings(check_timeout_seconds=0)
+    with pytest.raises(ValidationError):
+        Settings(max_redirects=99)