diff --git a/resources/tester/test_591_1_plan_site.py b/resources/tester/test_591_1_plan_site.py
index 5fbcc8098..e620be9e1 100644
--- a/resources/tester/test_591_1_plan_site.py
+++ b/resources/tester/test_591_1_plan_site.py
@@ -105,3 +105,10 @@ def test_화면_지도_출처():
     assert "editMap(" in page and "/map/address" in page and "DE_Reg_SiteSource" in page
     assert "site: { lon: at[0], lat: at[1] }" in page and "DE_Reg_SiteRequired" in page
     assert "DesignSpeed" not in page
+
+
+def test_D04_연결_설계속도_안_넘김(monkeypatch):
+    from D04_PlanConfirm import D04_PlanConfirm_Link as link
+
+    monkeypatch.setattr(link, "get_db_pool", lambda: pytest.fail("빈 설계속도는 씨앗 안 씀"))
+    asyncio.run(link.seed_design_speed("road-id", None))  # 예정노선 = 빈 값 → B05 기본 20