diff --git a/pandas/tests/series/indexing/test_setitem.py b/pandas/tests/series/indexing/test_setitem.py
index f894005296781..34ca256a5d1ea 100644
--- a/pandas/tests/series/indexing/test_setitem.py
+++ b/pandas/tests/series/indexing/test_setitem.py
@@ -1025,7 +1025,7 @@ class TestSetitemNAPeriodDtype(SetitemCastingEquivalents):
     def expected(self, key):
         exp = Series(period_range("2000-01-01", periods=10, freq="D"))
         exp._values.view("i8")[key] = NaT._value
-        assert exp[key] is NaT or all(x is NaT for x in exp[key])
+        assert exp[key] is NaT or any(x is NaT for x in exp)
         return exp
 
     @pytest.fixture