diff --git a/tests/test_amsc_awos_sources.py b/tests/test_amsc_awos_sources.py
index c6d1fb90..52d7fece 100644
--- a/tests/test_amsc_awos_sources.py
+++ b/tests/test_amsc_awos_sources.py
@@ -73,7 +73,8 @@ def test_parse_wind_plate_payload_rejects_unauthorized_or_empty_payloads():
     assert _amsc_parse_wind_plate_payload({"code": 200, "data": {}}, city_key="beijing", icao="ZBAA") is None
 
 
-def test_fetch_amsc_official_current_uses_domestic_city_whitelist():
+def test_fetch_amsc_official_current_uses_domestic_city_whitelist(monkeypatch):
+    monkeypatch.setenv("AMSC_AWOS_BASE_URL", "https://www.amsc.net.cn/gateway/api/saas/rest/amc/AwosController/getWindPlate")
     assert _amsc_supported_city_codes()["beijing"] == "ZBAA"
     assert "new york" not in _amsc_supported_city_codes()
 
diff --git a/tests/test_nmc_sources.py b/tests/test_nmc_sources.py
index d43bd3d1..4caf1eea 100644
--- a/tests/test_nmc_sources.py
+++ b/tests/test_nmc_sources.py
@@ -40,7 +40,8 @@ class _DummyCollector(NmcSourceMixin):
         self._nmc_cache_lock = threading.Lock()
 
 
-def test_fetch_nmc_region_current_parses_rest_payload():
+def test_fetch_nmc_region_current_parses_rest_payload(monkeypatch):
+    monkeypatch.setenv("NMC_REALTIME_BASE_URL", "https://www.nmc.cn/rest/real")
     collector = _DummyCollector(
         {
             "https://www.nmc.cn/rest/real/atcMf": _DummyResponse(
@@ -70,7 +71,8 @@ def test_fetch_nmc_region_current_parses_rest_payload():
     assert out["current"]["airpressure"] is None
 
 
-def test_fetch_nmc_official_nearby_returns_normalized_row():
+def test_fetch_nmc_official_nearby_returns_normalized_row(monkeypatch):
+    monkeypatch.setenv("NMC_REALTIME_BASE_URL", "https://www.nmc.cn/rest/real")
     collector = _DummyCollector(
         {
             "https://www.nmc.cn/rest/real/atcMf": _DummyResponse(