diff --git a/tests/unit_tests/weightwindows/test_ww_gen.py b/tests/unit_tests/weightwindows/test_ww_gen.py
index a5f65ff617..a1aaca5b0e 100644
--- a/tests/unit_tests/weightwindows/test_ww_gen.py
+++ b/tests/unit_tests/weightwindows/test_ww_gen.py
@@ -229,9 +229,9 @@ def test_ww_gen_roundtrip(run_in_tmpdir, model):
     particle_type = 'neutron'
 
     wwg = openmc.WeightWindowGenerator(mesh, energy_bounds, particle_type)
-    wwg.update_params = {'ratio' : 5.0,
-                         'threshold': 0.8,
-                         'value' : 'mean'}
+    wwg.update_parameters = {'ratio' : 5.0,
+                             'threshold': 0.8,
+                             'value' : 'mean'}
 
     model.settings.weight_window_generators = wwg
     model.export_to_xml()