diff --git a/tests/test_p0_standings_cutoff.py b/tests/test_p0_standings_cutoff.py
index 09ad71b..3b9d397 100644
--- a/tests/test_p0_standings_cutoff.py
+++ b/tests/test_p0_standings_cutoff.py
@@ -73,7 +73,9 @@ class TestStandingsModel:
 
     def test_unique_constraint_includes_available_at(self):
         names = {c.name for c in Standing.__table__.constraints}
-        assert any("available" in n and n.startswith("uq_") for n in names), \
+        # 匿名约束(PK/Check)的 name 是 None,必须先判真值再子串匹配,
+        # 否则 any() 撞上 None 直接 TypeError(集合顺序不定 → flaky)
+        assert any(n and "available" in n and n.startswith("uq_") for n in names), \
             f"缺少含 available_at 的唯一约束,现有: {names}"
 
     def test_old_unique_constraint_removed(self):