diff --git a/tests/test_basic/test_basic.py b/tests/test_basic/test_basic.py
index 390e6d832e..6633e59111 100755
--- a/tests/test_basic/test_basic.py
+++ b/tests/test_basic/test_basic.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_cmfd_feed/test_cmfd_feed.py b/tests/test_cmfd_feed/test_cmfd_feed.py
index 8f4aeacb21..a3d2f30310 100644
--- a/tests/test_cmfd_feed/test_cmfd_feed.py
+++ b/tests/test_cmfd_feed/test_cmfd_feed.py
@@ -7,4 +7,4 @@ from testing_harness import CMFDTestHarness
 
 if __name__ == '__main__':
     harness = CMFDTestHarness('statepoint.20.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_cmfd_nofeed/test_cmfd_nofeed.py b/tests/test_cmfd_nofeed/test_cmfd_nofeed.py
index 8f4aeacb21..a3d2f30310 100644
--- a/tests/test_cmfd_nofeed/test_cmfd_nofeed.py
+++ b/tests/test_cmfd_nofeed/test_cmfd_nofeed.py
@@ -7,4 +7,4 @@ from testing_harness import CMFDTestHarness
 
 if __name__ == '__main__':
     harness = CMFDTestHarness('statepoint.20.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_confidence_intervals/test_confidence_intervals.py b/tests/test_confidence_intervals/test_confidence_intervals.py
index 8f3b0785a8..1777db993e 100755
--- a/tests/test_confidence_intervals/test_confidence_intervals.py
+++ b/tests/test_confidence_intervals/test_confidence_intervals.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_density_atombcm/test_density_atombcm.py b/tests/test_density_atombcm/test_density_atombcm.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_density_atombcm/test_density_atombcm.py
+++ b/tests/test_density_atombcm/test_density_atombcm.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_density_atomcm3/test_density_atomcm3.py b/tests/test_density_atomcm3/test_density_atomcm3.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_density_atomcm3/test_density_atomcm3.py
+++ b/tests/test_density_atomcm3/test_density_atomcm3.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_density_kgm3/test_density_kgm3.py b/tests/test_density_kgm3/test_density_kgm3.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_density_kgm3/test_density_kgm3.py
+++ b/tests/test_density_kgm3/test_density_kgm3.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_density_sum/test_density_sum.py b/tests/test_density_sum/test_density_sum.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_density_sum/test_density_sum.py
+++ b/tests/test_density_sum/test_density_sum.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_eigenvalue_genperbatch/test_eigenvalue_genperbatch.py b/tests/test_eigenvalue_genperbatch/test_eigenvalue_genperbatch.py
index 745c9e706d..22752c1894 100644
--- a/tests/test_eigenvalue_genperbatch/test_eigenvalue_genperbatch.py
+++ b/tests/test_eigenvalue_genperbatch/test_eigenvalue_genperbatch.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.7.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_eigenvalue_no_inactive/test_eigenvalue_no_inactive.py b/tests/test_eigenvalue_no_inactive/test_eigenvalue_no_inactive.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_eigenvalue_no_inactive/test_eigenvalue_no_inactive.py
+++ b/tests/test_eigenvalue_no_inactive/test_eigenvalue_no_inactive.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_energy_grid/test_energy_grid.py b/tests/test_energy_grid/test_energy_grid.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_energy_grid/test_energy_grid.py
+++ b/tests/test_energy_grid/test_energy_grid.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_entropy/test_entropy.py b/tests/test_entropy/test_entropy.py
index 9f908900b2..4657101ad6 100644
--- a/tests/test_entropy/test_entropy.py
+++ b/tests/test_entropy/test_entropy.py
@@ -28,4 +28,4 @@ class EntropyTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = EntropyTestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_cell/test_filter_cell.py b/tests/test_filter_cell/test_filter_cell.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_cell/test_filter_cell.py
+++ b/tests/test_filter_cell/test_filter_cell.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_cellborn/test_filter_cellborn.py b/tests/test_filter_cellborn/test_filter_cellborn.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_cellborn/test_filter_cellborn.py
+++ b/tests/test_filter_cellborn/test_filter_cellborn.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_distribcell/test_filter_distribcell.py b/tests/test_filter_distribcell/test_filter_distribcell.py
index 0513227488..b5895f81b9 100644
--- a/tests/test_filter_distribcell/test_filter_distribcell.py
+++ b/tests/test_filter_distribcell/test_filter_distribcell.py
@@ -15,7 +15,7 @@ class DistribcellTestHarness(TestHarness):
         self._args = None
 
     def execute_test(self):
-        self._parse_args()
+        """Run OpenMC with the appropriate arguments and check the outputs."""
         base_dir = os.getcwd()
         try:
             dirs = ('case-1', '../case-2', '../case-3')
@@ -37,6 +37,29 @@ class DistribcellTestHarness(TestHarness):
                 os.chdir(dirs[i])
                 self._cleanup()
 
+    def update_results(self):
+        """Update the results_true using the current version of OpenMC."""
+        base_dir = os.getcwd()
+        try:
+            dirs = ('case-1', '../case-2', '../case-3')
+            sps = ('statepoint.1.*', 'statepoint.1.*', 'statepoint.3.*')
+            tallies_out_present = (True, True, False)
+            hash_out = (False, False, True)
+            for i in range(len(dirs)):
+                os.chdir(dirs[i])
+                self._sp_name = sps[i]
+
+                self._run_openmc()
+                self._test_output_created(tallies_out_present[i])
+                results = self._get_results(hash_out[i])
+                self._write_results(results)
+                self._overwrite_results()
+        finally:
+            os.chdir(base_dir)
+            for i in range(len(dirs)):
+                os.chdir(dirs[i])
+                self._cleanup()
+
     def _test_output_created(self, tallies_out_present):
         """Make sure statepoint.* and tallies.out have been created."""
         statepoint = glob.glob(os.path.join(os.getcwd(), self._sp_name))
@@ -52,4 +75,4 @@ class DistribcellTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = DistribcellTestHarness()
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_energy/test_filter_energy.py b/tests/test_filter_energy/test_filter_energy.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_energy/test_filter_energy.py
+++ b/tests/test_filter_energy/test_filter_energy.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_energyout/test_filter_energyout.py b/tests/test_filter_energyout/test_filter_energyout.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_energyout/test_filter_energyout.py
+++ b/tests/test_filter_energyout/test_filter_energyout.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_group_transfer/test_filter_group_transfer.py b/tests/test_filter_group_transfer/test_filter_group_transfer.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_group_transfer/test_filter_group_transfer.py
+++ b/tests/test_filter_group_transfer/test_filter_group_transfer.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_material/test_filter_material.py b/tests/test_filter_material/test_filter_material.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_material/test_filter_material.py
+++ b/tests/test_filter_material/test_filter_material.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_mesh_2d/test_filter_mesh_2d.py b/tests/test_filter_mesh_2d/test_filter_mesh_2d.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_mesh_2d/test_filter_mesh_2d.py
+++ b/tests/test_filter_mesh_2d/test_filter_mesh_2d.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_mesh_3d/test_filter_mesh_3d.py b/tests/test_filter_mesh_3d/test_filter_mesh_3d.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_mesh_3d/test_filter_mesh_3d.py
+++ b/tests/test_filter_mesh_3d/test_filter_mesh_3d.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_filter_universe/test_filter_universe.py b/tests/test_filter_universe/test_filter_universe.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_filter_universe/test_filter_universe.py
+++ b/tests/test_filter_universe/test_filter_universe.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_fixed_source/test_fixed_source.py b/tests/test_fixed_source/test_fixed_source.py
index 74de412b9e..1f4382c08f 100644
--- a/tests/test_fixed_source/test_fixed_source.py
+++ b/tests/test_fixed_source/test_fixed_source.py
@@ -33,4 +33,4 @@ class FixedSourceTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = FixedSourceTestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_infinite_cell/test_infinite_cell.py b/tests/test_infinite_cell/test_infinite_cell.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_infinite_cell/test_infinite_cell.py
+++ b/tests/test_infinite_cell/test_infinite_cell.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_lattice/test_lattice.py b/tests/test_lattice/test_lattice.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_lattice/test_lattice.py
+++ b/tests/test_lattice/test_lattice.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_lattice_hex/test_lattice_hex.py b/tests/test_lattice_hex/test_lattice_hex.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_lattice_hex/test_lattice_hex.py
+++ b/tests/test_lattice_hex/test_lattice_hex.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_lattice_mixed/test_lattice_mixed.py b/tests/test_lattice_mixed/test_lattice_mixed.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_lattice_mixed/test_lattice_mixed.py
+++ b/tests/test_lattice_mixed/test_lattice_mixed.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_lattice_multiple/test_lattice_multiple.py b/tests/test_lattice_multiple/test_lattice_multiple.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_lattice_multiple/test_lattice_multiple.py
+++ b/tests/test_lattice_multiple/test_lattice_multiple.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_many_scores/test_many_scores.py b/tests/test_many_scores/test_many_scores.py
index c1a8684102..66bfe3dfa7 100644
--- a/tests/test_many_scores/test_many_scores.py
+++ b/tests/test_many_scores/test_many_scores.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.5.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_natural_element/test_natural_element.py b/tests/test_natural_element/test_natural_element.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_natural_element/test_natural_element.py
+++ b/tests/test_natural_element/test_natural_element.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_output/test_output.py b/tests/test_output/test_output.py
index b890cb7b66..1f51742ba2 100644
--- a/tests/test_output/test_output.py
+++ b/tests/test_output/test_output.py
@@ -32,4 +32,4 @@ class OutputTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = OutputTestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_particle_restart_eigval/test_particle_restart_eigval.py b/tests/test_particle_restart_eigval/test_particle_restart_eigval.py
index 4b4ca6750f..64123b2e09 100644
--- a/tests/test_particle_restart_eigval/test_particle_restart_eigval.py
+++ b/tests/test_particle_restart_eigval/test_particle_restart_eigval.py
@@ -7,4 +7,4 @@ from testing_harness import ParticleRestartTestHarness
 
 if __name__ == '__main__':
     harness = ParticleRestartTestHarness('particle_12_616.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_particle_restart_fixed/test_particle_restart_fixed.py b/tests/test_particle_restart_fixed/test_particle_restart_fixed.py
index 9723421a46..05dcf76a68 100644
--- a/tests/test_particle_restart_fixed/test_particle_restart_fixed.py
+++ b/tests/test_particle_restart_fixed/test_particle_restart_fixed.py
@@ -7,4 +7,4 @@ from testing_harness import ParticleRestartTestHarness
 
 if __name__ == '__main__':
     harness = ParticleRestartTestHarness('particle_7_6144.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_plot_background/test_plot_background.py b/tests/test_plot_background/test_plot_background.py
index 9eec6c0b9f..49cdacb05c 100644
--- a/tests/test_plot_background/test_plot_background.py
+++ b/tests/test_plot_background/test_plot_background.py
@@ -7,4 +7,4 @@ from testing_harness import PlotTestHarness
 
 if __name__ == '__main__':
     harness = PlotTestHarness(('1_plot.ppm', ))
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_plot_basis/test_plot_basis.py b/tests/test_plot_basis/test_plot_basis.py
index b1c58979fb..85e30557d2 100644
--- a/tests/test_plot_basis/test_plot_basis.py
+++ b/tests/test_plot_basis/test_plot_basis.py
@@ -7,4 +7,4 @@ from testing_harness import PlotTestHarness
 
 if __name__ == '__main__':
     harness = PlotTestHarness(('1_plot.ppm', '2_plot.ppm', '3_plot.ppm'))
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_plot_colspec/test_plot_colspec.py b/tests/test_plot_colspec/test_plot_colspec.py
index 9eec6c0b9f..49cdacb05c 100644
--- a/tests/test_plot_colspec/test_plot_colspec.py
+++ b/tests/test_plot_colspec/test_plot_colspec.py
@@ -7,4 +7,4 @@ from testing_harness import PlotTestHarness
 
 if __name__ == '__main__':
     harness = PlotTestHarness(('1_plot.ppm', ))
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_plot_mask/test_plot_mask.py b/tests/test_plot_mask/test_plot_mask.py
index b1c58979fb..85e30557d2 100644
--- a/tests/test_plot_mask/test_plot_mask.py
+++ b/tests/test_plot_mask/test_plot_mask.py
@@ -7,4 +7,4 @@ from testing_harness import PlotTestHarness
 
 if __name__ == '__main__':
     harness = PlotTestHarness(('1_plot.ppm', '2_plot.ppm', '3_plot.ppm'))
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_ptables_off/test_ptables_off.py b/tests/test_ptables_off/test_ptables_off.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_ptables_off/test_ptables_off.py
+++ b/tests/test_ptables_off/test_ptables_off.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_reflective_cone/test_reflective_cone.py b/tests/test_reflective_cone/test_reflective_cone.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_reflective_cone/test_reflective_cone.py
+++ b/tests/test_reflective_cone/test_reflective_cone.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_reflective_cylinder/test_reflective_cylinder.py b/tests/test_reflective_cylinder/test_reflective_cylinder.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_reflective_cylinder/test_reflective_cylinder.py
+++ b/tests/test_reflective_cylinder/test_reflective_cylinder.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_reflective_plane/test_reflective_plane.py b/tests/test_reflective_plane/test_reflective_plane.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_reflective_plane/test_reflective_plane.py
+++ b/tests/test_reflective_plane/test_reflective_plane.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_reflective_sphere/test_reflective_sphere.py b/tests/test_reflective_sphere/test_reflective_sphere.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_reflective_sphere/test_reflective_sphere.py
+++ b/tests/test_reflective_sphere/test_reflective_sphere.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_resonance_scattering/test_resonance_scattering.py b/tests/test_resonance_scattering/test_resonance_scattering.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_resonance_scattering/test_resonance_scattering.py
+++ b/tests/test_resonance_scattering/test_resonance_scattering.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_rotation/test_rotation.py b/tests/test_rotation/test_rotation.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_rotation/test_rotation.py
+++ b/tests/test_rotation/test_rotation.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_salphabeta/test_salphabeta.py b/tests/test_salphabeta/test_salphabeta.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_salphabeta/test_salphabeta.py
+++ b/tests/test_salphabeta/test_salphabeta.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_salphabeta_multiple/test_salphabeta_multiple.py b/tests/test_salphabeta_multiple/test_salphabeta_multiple.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_salphabeta_multiple/test_salphabeta_multiple.py
+++ b/tests/test_salphabeta_multiple/test_salphabeta_multiple.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_MT/test_score_MT.py b/tests/test_score_MT/test_score_MT.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_MT/test_score_MT.py
+++ b/tests/test_score_MT/test_score_MT.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_absorption/test_score_absorption.py b/tests/test_score_absorption/test_score_absorption.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_absorption/test_score_absorption.py
+++ b/tests/test_score_absorption/test_score_absorption.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_current/test_score_current.py b/tests/test_score_current/test_score_current.py
index 45c433691a..64f640b96c 100644
--- a/tests/test_score_current/test_score_current.py
+++ b/tests/test_score_current/test_score_current.py
@@ -7,4 +7,4 @@ from testing_harness import HashedTestHarness
 
 if __name__ == '__main__':
     harness = HashedTestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_events/test_score_events.py b/tests/test_score_events/test_score_events.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_events/test_score_events.py
+++ b/tests/test_score_events/test_score_events.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_fission/test_score_fission.py b/tests/test_score_fission/test_score_fission.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_fission/test_score_fission.py
+++ b/tests/test_score_fission/test_score_fission.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_flux/test_score_flux.py b/tests/test_score_flux/test_score_flux.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_flux/test_score_flux.py
+++ b/tests/test_score_flux/test_score_flux.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_flux_yn/test_score_flux_yn.py b/tests/test_score_flux_yn/test_score_flux_yn.py
index 8f3b0785a8..1777db993e 100755
--- a/tests/test_score_flux_yn/test_score_flux_yn.py
+++ b/tests/test_score_flux_yn/test_score_flux_yn.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_kappafission/test_score_kappafission.py b/tests/test_score_kappafission/test_score_kappafission.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_kappafission/test_score_kappafission.py
+++ b/tests/test_score_kappafission/test_score_kappafission.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_nufission/test_score_nufission.py b/tests/test_score_nufission/test_score_nufission.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_nufission/test_score_nufission.py
+++ b/tests/test_score_nufission/test_score_nufission.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_nuscatter/test_score_nuscatter.py b/tests/test_score_nuscatter/test_score_nuscatter.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_nuscatter/test_score_nuscatter.py
+++ b/tests/test_score_nuscatter/test_score_nuscatter.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_nuscatter_n/test_score_nuscatter_n.py b/tests/test_score_nuscatter_n/test_score_nuscatter_n.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_nuscatter_n/test_score_nuscatter_n.py
+++ b/tests/test_score_nuscatter_n/test_score_nuscatter_n.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_nuscatter_pn/test_score_nuscatter_pn.py b/tests/test_score_nuscatter_pn/test_score_nuscatter_pn.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_nuscatter_pn/test_score_nuscatter_pn.py
+++ b/tests/test_score_nuscatter_pn/test_score_nuscatter_pn.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_nuscatter_yn/test_score_nuscatter_yn.py b/tests/test_score_nuscatter_yn/test_score_nuscatter_yn.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_nuscatter_yn/test_score_nuscatter_yn.py
+++ b/tests/test_score_nuscatter_yn/test_score_nuscatter_yn.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_scatter/test_score_scatter.py b/tests/test_score_scatter/test_score_scatter.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_scatter/test_score_scatter.py
+++ b/tests/test_score_scatter/test_score_scatter.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_scatter_n/test_score_scatter_n.py b/tests/test_score_scatter_n/test_score_scatter_n.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_scatter_n/test_score_scatter_n.py
+++ b/tests/test_score_scatter_n/test_score_scatter_n.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_scatter_pn/test_score_scatter_pn.py b/tests/test_score_scatter_pn/test_score_scatter_pn.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_scatter_pn/test_score_scatter_pn.py
+++ b/tests/test_score_scatter_pn/test_score_scatter_pn.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_scatter_yn/test_score_scatter_yn.py b/tests/test_score_scatter_yn/test_score_scatter_yn.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_scatter_yn/test_score_scatter_yn.py
+++ b/tests/test_score_scatter_yn/test_score_scatter_yn.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_total/test_score_total.py b/tests/test_score_total/test_score_total.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_total/test_score_total.py
+++ b/tests/test_score_total/test_score_total.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_score_total_yn/test_score_total_yn.py b/tests/test_score_total_yn/test_score_total_yn.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_score_total_yn/test_score_total_yn.py
+++ b/tests/test_score_total_yn/test_score_total_yn.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_seed/test_seed.py b/tests/test_seed/test_seed.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_seed/test_seed.py
+++ b/tests/test_seed/test_seed.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_source_angle_mono/test_source_angle_mono.py b/tests/test_source_angle_mono/test_source_angle_mono.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_source_angle_mono/test_source_angle_mono.py
+++ b/tests/test_source_angle_mono/test_source_angle_mono.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_source_energy_maxwell/test_source_energy_maxwell.py b/tests/test_source_energy_maxwell/test_source_energy_maxwell.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_source_energy_maxwell/test_source_energy_maxwell.py
+++ b/tests/test_source_energy_maxwell/test_source_energy_maxwell.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_source_energy_mono/test_source_energy_mono.py b/tests/test_source_energy_mono/test_source_energy_mono.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_source_energy_mono/test_source_energy_mono.py
+++ b/tests/test_source_energy_mono/test_source_energy_mono.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_source_file/test_source_file.py b/tests/test_source_file/test_source_file.py
index cc146e5c9f..1750d60805 100644
--- a/tests/test_source_file/test_source_file.py
+++ b/tests/test_source_file/test_source_file.py
@@ -38,7 +38,7 @@ settings2 = """<?xml version="1.0"?>
 
 class SourceFileTestHarness(TestHarness):
     def execute_test(self):
-        self._parse_args()
+        """Run OpenMC with the appropriate arguments and check the outputs."""
         try:
             self._run_openmc()
             self._test_output_created()
@@ -49,6 +49,18 @@ class SourceFileTestHarness(TestHarness):
         finally:
             self._cleanup()
 
+    def update_results(self):
+        """Update the results_true using the current version of OpenMC."""
+        try:
+            self._run_openmc()
+            self._test_output_created()
+            self._run_openmc_restart()
+            results = self._get_results()
+            self._write_results(results)
+            self._overwrite_results()
+        finally:
+            self._cleanup()
+
     def _test_output_created(self):
         """Make sure statepoint and source files have been created."""
         statepoint = glob.glob(os.path.join(os.getcwd(), self._sp_name))
@@ -95,4 +107,4 @@ class SourceFileTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = SourceFileTestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_source_point/test_source_point.py b/tests/test_source_point/test_source_point.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_source_point/test_source_point.py
+++ b/tests/test_source_point/test_source_point.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_sourcepoint_batch/test_sourcepoint_batch.py b/tests/test_sourcepoint_batch/test_sourcepoint_batch.py
index efcc03718f..8cafb41084 100644
--- a/tests/test_sourcepoint_batch/test_sourcepoint_batch.py
+++ b/tests/test_sourcepoint_batch/test_sourcepoint_batch.py
@@ -35,4 +35,4 @@ class SourcepointTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = SourcepointTestHarness('statepoint.08.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_sourcepoint_interval/test_sourcepoint_interval.py b/tests/test_sourcepoint_interval/test_sourcepoint_interval.py
index efcc03718f..8cafb41084 100644
--- a/tests/test_sourcepoint_interval/test_sourcepoint_interval.py
+++ b/tests/test_sourcepoint_interval/test_sourcepoint_interval.py
@@ -35,4 +35,4 @@ class SourcepointTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = SourcepointTestHarness('statepoint.08.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_sourcepoint_latest/test_sourcepoint_latest.py b/tests/test_sourcepoint_latest/test_sourcepoint_latest.py
index 5929865ded..5ae3984626 100644
--- a/tests/test_sourcepoint_latest/test_sourcepoint_latest.py
+++ b/tests/test_sourcepoint_latest/test_sourcepoint_latest.py
@@ -19,4 +19,4 @@ class SourcepointTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_sourcepoint_restart/test_sourcepoint_restart.py b/tests/test_sourcepoint_restart/test_sourcepoint_restart.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_sourcepoint_restart/test_sourcepoint_restart.py
+++ b/tests/test_sourcepoint_restart/test_sourcepoint_restart.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_statepoint_batch/test_statepoint_batch.py b/tests/test_statepoint_batch/test_statepoint_batch.py
index ceedcd3779..bc5632618f 100644
--- a/tests/test_statepoint_batch/test_statepoint_batch.py
+++ b/tests/test_statepoint_batch/test_statepoint_batch.py
@@ -21,4 +21,4 @@ class StatepointTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = StatepointTestHarness()
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_statepoint_interval/test_statepoint_interval.py b/tests/test_statepoint_interval/test_statepoint_interval.py
index 6772bce374..b41ee2b7ae 100644
--- a/tests/test_statepoint_interval/test_statepoint_interval.py
+++ b/tests/test_statepoint_interval/test_statepoint_interval.py
@@ -23,4 +23,4 @@ class StatepointTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = StatepointTestHarness()
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_statepoint_restart/test_statepoint_restart.py b/tests/test_statepoint_restart/test_statepoint_restart.py
index 8d960128dd..739ce84a9f 100644
--- a/tests/test_statepoint_restart/test_statepoint_restart.py
+++ b/tests/test_statepoint_restart/test_statepoint_restart.py
@@ -7,7 +7,7 @@ from testing_harness import *
 
 class StatepointRestartTestHarness(TestHarness):
     def execute_test(self):
-        self._parse_args()
+        """Run OpenMC with the appropriate arguments and check the outputs."""
         try:
             self._run_openmc()
             self._test_output_created()
@@ -23,6 +23,17 @@ class StatepointRestartTestHarness(TestHarness):
         finally:
             self._cleanup()
 
+    def update_results(self):
+        """Update the results_true using the current version of OpenMC."""
+        try:
+            self._run_openmc()
+            self._test_output_created()
+            results = self._get_results()
+            self._write_results(results)
+            self._overwrite_results()
+        finally:
+            self._cleanup()
+
     def _run_openmc_restart(self):
         # Get the number of MPI processes.
         if self._opts.mpi_exec:
@@ -42,4 +53,4 @@ class StatepointRestartTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = StatepointRestartTestHarness('statepoint.07.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_statepoint_sourcesep/test_statepoint_sourcesep.py b/tests/test_statepoint_sourcesep/test_statepoint_sourcesep.py
index bd78c3ea0f..861a04f189 100644
--- a/tests/test_statepoint_sourcesep/test_statepoint_sourcesep.py
+++ b/tests/test_statepoint_sourcesep/test_statepoint_sourcesep.py
@@ -19,4 +19,4 @@ class SourcepointTestHarness(TestHarness):
 
 if __name__ == '__main__':
     harness = SourcepointTestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_survival_biasing/test_survival_biasing.py b/tests/test_survival_biasing/test_survival_biasing.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_survival_biasing/test_survival_biasing.py
+++ b/tests/test_survival_biasing/test_survival_biasing.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_tally_assumesep/test_tally_assumesep.py b/tests/test_tally_assumesep/test_tally_assumesep.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_tally_assumesep/test_tally_assumesep.py
+++ b/tests/test_tally_assumesep/test_tally_assumesep.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_tally_nuclides/test_tally_nuclides.py b/tests/test_tally_nuclides/test_tally_nuclides.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_tally_nuclides/test_tally_nuclides.py
+++ b/tests/test_tally_nuclides/test_tally_nuclides.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_trace/test_trace.py b/tests/test_trace/test_trace.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_trace/test_trace.py
+++ b/tests/test_trace/test_trace.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_track_output/test_track_output.py b/tests/test_track_output/test_track_output.py
index a778ded68e..31d29b7420 100644
--- a/tests/test_track_output/test_track_output.py
+++ b/tests/test_track_output/test_track_output.py
@@ -53,4 +53,4 @@ if __name__ == '__main__':
         shutil.copy('results_true.dat', 'results_test.dat')
         exit()
     harness = TrackTestHarness('statepoint.2.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_translation/test_translation.py b/tests/test_translation/test_translation.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_translation/test_translation.py
+++ b/tests/test_translation/test_translation.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_trigger_batch_interval/test_trigger_batch_interval.py b/tests/test_trigger_batch_interval/test_trigger_batch_interval.py
index 219089d131..d5e176fea9 100644
--- a/tests/test_trigger_batch_interval/test_trigger_batch_interval.py
+++ b/tests/test_trigger_batch_interval/test_trigger_batch_interval.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.19.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_trigger_no_batch_interval/test_trigger_no_batch_interval.py b/tests/test_trigger_no_batch_interval/test_trigger_no_batch_interval.py
index 219089d131..d5e176fea9 100644
--- a/tests/test_trigger_no_batch_interval/test_trigger_no_batch_interval.py
+++ b/tests/test_trigger_no_batch_interval/test_trigger_no_batch_interval.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.19.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_trigger_no_status/test_trigger_no_status.py b/tests/test_trigger_no_status/test_trigger_no_status.py
index 8f3b0785a8..1777db993e 100644
--- a/tests/test_trigger_no_status/test_trigger_no_status.py
+++ b/tests/test_trigger_no_status/test_trigger_no_status.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_trigger_tallies/test_trigger_tallies.py b/tests/test_trigger_tallies/test_trigger_tallies.py
index a77e996e50..20094827e0 100644
--- a/tests/test_trigger_tallies/test_trigger_tallies.py
+++ b/tests/test_trigger_tallies/test_trigger_tallies.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.15.*', True)
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_uniform_fs/test_uniform_fs.py b/tests/test_uniform_fs/test_uniform_fs.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_uniform_fs/test_uniform_fs.py
+++ b/tests/test_uniform_fs/test_uniform_fs.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_union_energy_grids/test_union_energy_grids.py b/tests/test_union_energy_grids/test_union_energy_grids.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_union_energy_grids/test_union_energy_grids.py
+++ b/tests/test_union_energy_grids/test_union_energy_grids.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_universe/test_universe.py b/tests/test_universe/test_universe.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_universe/test_universe.py
+++ b/tests/test_universe/test_universe.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/test_void/test_void.py b/tests/test_void/test_void.py
index 390e6d832e..6633e59111 100644
--- a/tests/test_void/test_void.py
+++ b/tests/test_void/test_void.py
@@ -7,4 +7,4 @@ from testing_harness import TestHarness
 
 if __name__ == '__main__':
     harness = TestHarness('statepoint.10.*')
-    harness.execute_test()
+    harness.main()
diff --git a/tests/testing_harness.py b/tests/testing_harness.py
index 2363aaff35..6d35ef9786 100644
--- a/tests/testing_harness.py
+++ b/tests/testing_harness.py
@@ -5,6 +5,7 @@ import glob
 import hashlib
 from optparse import OptionParser
 import os
+import shutil
 from subprocess import Popen, STDOUT, PIPE, call
 import sys
 
@@ -24,9 +25,16 @@ class TestHarness(object):
         self._opts = None
         self._args = None
 
+    def main(self):
+        """Accept commandline arguments and either run or update tests."""
+        self._parse_args()
+        if self._opts.update:
+            self.update_results()
+        else:
+            self.execute_test()
+
     def execute_test(self):
         """Run OpenMC with the appropriate arguments and check the outputs."""
-        self._parse_args()
         try:
             self._run_openmc()
             self._test_output_created()
@@ -36,11 +44,24 @@ class TestHarness(object):
         finally:
             self._cleanup()
 
+    def update_results(self):
+        """Update the results_true using the current version of OpenMC."""
+        try:
+            self._run_openmc()
+            self._test_output_created()
+            results = self._get_results()
+            self._write_results(results)
+            self._overwrite_results()
+        finally:
+            self._cleanup()
+
     def _parse_args(self):
         parser = OptionParser()
         parser.add_option('--mpi_exec', dest='mpi_exec', action='store_true',
                           default=False)
         parser.add_option('--mpi_np', dest='mpi_np', type=int, default=3)
+        parser.add_option('--update', dest='update', action='store_true',
+                          default=False)
         (self._opts, self._args) = parser.parse_args()
 
     def _run_openmc(self):
@@ -104,6 +125,10 @@ class TestHarness(object):
         with open('results_test.dat','w') as fh:
             fh.write(results_string)
 
+    def _overwrite_results(self):
+        """Overwrite the results_true with the results_test."""
+        shutil.copyfile('results_test.dat', 'results_true.dat')
+
     def _compare_results(self):
         compare = filecmp.cmp('results_test.dat', 'results_true.dat')
         if not compare:
diff --git a/tests/update_results.py b/tests/update_results.py
index 5b785fc59c..5656003331 100755
--- a/tests/update_results.py
+++ b/tests/update_results.py
@@ -9,9 +9,6 @@ from glob import glob
 from optparse import OptionParser
 
 parser = OptionParser()
-parser.add_option('--exe', dest='exe',
-                  help="Path to openmc executable with basic \
-                        configuration options (no HDF5, no MPI, etc.)")
 parser.add_option('-R', '--tests-regex', dest='regex_tests',
                   help="Run tests matching regular expression. \
                   Test names are the directories present in tests folder.\
@@ -25,12 +22,6 @@ FAIL = '\033[91m'
 ENDC = '\033[0m'
 BOLD = '\033[1m'
 
-# Check for valid executable
-if opts.exe is None:
-    raise Exception('Need to specify an OpenMC executable')
-else:
-    openmc_exe = os.path.abspath(opts.exe)
-
 # Get a list of all test folders
 folders = glob('test_*')
 
@@ -41,10 +32,6 @@ if opts.regex_tests is not None:
 # Loop around directories
 for adir in sorted(folders):
 
-    # Skip test compile or plot
-    if adir.find('plot') != -1:
-        continue
-
     # Go into that directory
     os.chdir(adir)
     pwd = os.path.abspath(os.path.dirname('settings.xml'))
@@ -56,47 +43,18 @@ for adir in sorted(folders):
     for i in range(35 - sz):
         print('.', end="")
 
-    # Handle source file test separately since it requires running OpenMC twice
-    if adir == 'test_source_file':
-        if os.path.exists('results_error.dat'):
-            os.remove('results_error.dat')
-        proc = Popen(['python', 'test_source_file.py', '--exe', openmc_exe],
-                     stderr=STDOUT, stdout=PIPE)
-        returncode = proc.wait()
-        if os.path.exists('results_error.dat'):
-            os.rename('results_error.dat', 'results_true.dat')
-        print(BOLD + OKGREEN + "[OK]" + ENDC)
-        os.chdir('..')
-        continue
+    # Find the test executable
+    test_exec = glob('test_*.py')
+    assert len(test_exec) == 1, 'There must be only one test executable per ' \
+         'test directory'
 
-    # Handle distribcell test separately since it requires running OpenMC 3x
-    elif adir == 'test_filter_distribcell':
-        if os.path.exists('results_error.dat'):
-            os.remove('results_error.dat')
-        proc = Popen(['python', 'test_filter_distribcell.py',
-                      '--exe', openmc_exe], stderr=STDOUT, stdout=PIPE)
-        returncode = proc.wait()
-        if os.path.exists('results_error.dat'):
-            print('renamed results_error!!!')
-            os.rename('results_error.dat', 'results_true.dat')
-        print(BOLD + OKGREEN + "[OK]" + ENDC)
-        os.chdir('..')
-        continue
-
-    # Run openmc
-    proc = Popen([openmc_exe], stderr=STDOUT, stdout=PIPE)
+    # Update the test results
+    proc = Popen(['python', test_exec[0], '--update'])
     returncode = proc.wait()
     if returncode == 0:
         print(BOLD + OKGREEN + "[OK]" + ENDC)
     else:
         print(BOLD + FAIL + "[FAILED]" + ENDC)
 
-    # Process results
-    if returncode == 0:
-        call(['python', 'results.py'])
-        os.rename('results_test.dat', 'results_true.dat')
-        for path in glob("*.binary") + glob("*.out"):
-            os.remove(path)
-
     # Go back a directory
     os.chdir('..')