diff --git a/portfolyo/tools/testing.py b/portfolyo/tools/testing.py
index ed5c241..48da7eb 100644
--- a/portfolyo/tools/testing.py
+++ b/portfolyo/tools/testing.py
@@ -44,10 +44,12 @@ def assert_series_equal(left: pd.Series, right: pd.Series, *args, **kwargs):
     pd.testing.assert_series_equal(leftm, rightm, *args, **kwargs)
 
     # Units must be the same.
+    assert type(leftu) is type(rightu)
     if leftu is None:
         assert leftu is rightu
     elif isinstance(leftu, pint.Unit):  # all values share the same unit, leftu is Unit
-        assert leftu == rightu
+        # Use `1*` to turn back into quantity. Ensures 'MWh' and 'MW*h' are the same.
+        assert 1 * leftu == 1 * rightu
     else:  # each value has its own unit; leftu is Series
         pd.testing.assert_series_equal(leftu, rightu)
 
diff --git a/tests/core/pfline/test_flat_helper.py b/tests/core/pfline/test_flat_helper.py
index d629148..8f43ab5 100644
--- a/tests/core/pfline/test_flat_helper.py
+++ b/tests/core/pfline/test_flat_helper.py
@@ -69,7 +69,7 @@ def test_makedataframe_freqtz(freq, tz):
 
 
 @pytest.mark.parametrize("data,expected", TESTCASES_INPUTTYPES)
-def test_makedataframe_inputtypes(data: Any, expected: pd.DataFrame):
+def test_makedataframe_inputtypes(data: Any, expected: pd.DataFrame | type):
     """Test if dataframe can be created from various input types."""
     if type(expected) is type and issubclass(expected, Exception):
         with pytest.raises(expected):