diff --git a/tests/unit_tests/dagmc/test_model.py b/tests/unit_tests/dagmc/test_model.py
index d5de850ae87..48c2f2cfdfb 100644
--- a/tests/unit_tests/dagmc/test_model.py
+++ b/tests/unit_tests/dagmc/test_model.py
@@ -129,7 +129,7 @@ def test_model_differentiate_with_DAGMC():
     mat_vol = openmc.VolumeCalculation(mat_list, 1000000, ll, ur)
     cell_vol = openmc.VolumeCalculation(list(root.cells.values()), 1000000, ll, ur)
     model.settings.volume_calculations = [mat_vol, cell_vol]
-    model.init_lib()
+    model.init_lib()i # need to reinitialize the lib after differentiating the materials
     model.calculate_volumes(cwd=p)
     volume_after = np.sum([m.volume for m in model.materials if "fuel" in m.name])
     assert np.isclose(volume_before, volume_after)