diff --git a/pandas/tests/dtypes/test_concat.py b/pandas/tests/dtypes/test_concat.py index 1fbbd3356ae13..5a9ad732792ea 100644 --- a/pandas/tests/dtypes/test_concat.py +++ b/pandas/tests/dtypes/test_concat.py @@ -88,3 +88,14 @@ def test_concat_mismatched_categoricals_with_empty(): result = _concat.concat_compat([ser1._values, ser2._values]) expected = pd.concat([ser1, ser2])._values tm.assert_categorical_equal(result, expected) + + +@pytest.mark.parametrize("copy", [True, False]) +def test_concat_single_dataframe_tz_aware(copy): + # https://github.com/pandas-dev/pandas/issues/25257 + df = pd.DataFrame( + {"timestamp": [pd.Timestamp("2020-04-08 09:00:00.709949+0000", tz="UTC")]} + ) + expected = df.copy() + result = pd.concat([df], copy=copy) + tm.assert_frame_equal(result, expected)