diff --git a/tests/unit_tests/test_filters.py b/tests/unit_tests/test_filters.py
index f50a57fa5..ec051d9fd 100644
--- a/tests/unit_tests/test_filters.py
+++ b/tests/unit_tests/test_filters.py
@@ -242,11 +242,13 @@ def test_first_moment(run_in_tmpdir, box_model):
         assert first_score(sph_flux_tally) == approx(flux)
         assert first_score(zernike_tally) == approx(scatter)
 
+
 def test_energy():
     f = openmc.EnergyFilter.from_group_structure('CCFE-709')
     assert f.bins.shape == (709, 2)
     assert len(f.values) == 710
 
+
 def test_lethargy_bin_width():
     f = openmc.EnergyFilter.from_group_structure('VITAMIN-J-175')
     assert len(f.lethargy_bin_width) == 175