diff --git a/lib/iris/tests/unit/coords/test_Coord.py b/lib/iris/tests/unit/coords/test_Coord.py
index 218082386c..defe36591b 100644
--- a/lib/iris/tests/unit/coords/test_Coord.py
+++ b/lib/iris/tests/unit/coords/test_Coord.py
@@ -265,7 +265,6 @@ def test_monthly_non_contiguous(self):
                 [datetime(1990, 5, 1), datetime(1990, 6, 1)],
             ]
         )
-        expected = units.date2num(expected)
         points = expected.mean(axis=1)
         coord = iris.coords.AuxCoord(points=points, units=units, standard_name="time")
         with pytest.raises(