diff --git a/tests/unit_tests/test_ecephys.py b/tests/unit_tests/test_ecephys.py
index d8bb5cba5..0e5f417bd 100644
--- a/tests/unit_tests/test_ecephys.py
+++ b/tests/unit_tests/test_ecephys.py
@@ -162,7 +162,7 @@ def test_check_electrical_series_dtype_pass(self):
         electrical_series = ElectricalSeries(
             name="elec_series",
             description="desc",
-            data=np.ones((100, 5), dtype=float),
+            data=np.ones((100, 5), dtype=np.dtype("float64")),
             electrodes=electrodes,
             rate=30.0,
         )