diff --git a/D03_PlanAnalysis/D03_PlanAnalysis_Layers.py b/D03_PlanAnalysis/D03_PlanAnalysis_Layers.py
index 2e0b531a1..3e01d1ddc 100644
--- a/D03_PlanAnalysis/D03_PlanAnalysis_Layers.py
+++ b/D03_PlanAnalysis/D03_PlanAnalysis_Layers.py
@@ -181,7 +181,7 @@ def ensure_cadastral(processed: Path, box: Box, epsg: int) -> dict[str, Any]:
     atomic_write_json(
         key_path,
         {
-            "box": [round(v, 3) for v in box],
+            "box": [float(v) for v in box],
             "epsg": int(epsg),
             "count": len(features),
             "failed": failed,
diff --git a/resources/tester/test_569_1_plan_layers.py b/resources/tester/test_569_1_plan_layers.py
index d6a057a32..56fdf0019 100644
--- a/resources/tester/test_569_1_plan_layers.py
+++ b/resources/tester/test_569_1_plan_layers.py
@@ -112,6 +112,13 @@ def test_cadastral_fetch_once_then_grow(tmp_path, monkeypatch) -> None:
     assert fake.calls == 15 + 18  # 넓어지면 상자 통째로 다시(5.2 km = 6 × 3 조각)
 
 
+def test_cadastral_same_odd_box_kept(tmp_path, monkeypatch) -> None:
+    monkeypatch.setattr(layers, "request_vworld_wfs", FakeWfs())
+    odd = (243862.86880613962, 544271.5644142976, 245002.02265078452, 545528.8660732408)
+    assert layers.ensure_cadastral(tmp_path, odd, EPSG)["fetched"]
+    assert not layers.ensure_cadastral(tmp_path, odd, EPSG)["fetched"]  # 소수 끝자리까지 같은 상자
+
+
 def test_cadastral_failures(tmp_path, monkeypatch) -> None:
     monkeypatch.setattr(layers, "request_vworld_wfs", FakeWfs(fail=99))
     with pytest.raises(RuntimeError):