diff --git a/tests/regression_tests/dagmc/universes/inputs_true.dat b/tests/regression_tests/dagmc/universes/inputs_true.dat
index fdc8b07bc..e235c06a8 100644
--- a/tests/regression_tests/dagmc/universes/inputs_true.dat
+++ b/tests/regression_tests/dagmc/universes/inputs_true.dat
@@ -1,13 +1,21 @@
- |
+ |
+
+ 24.0 24.0
+ 2 2
+ -24.0 -24.0
+
+9 9
+9 9
+
-
-
+
+
diff --git a/tests/regression_tests/dagmc/universes/results_true.dat b/tests/regression_tests/dagmc/universes/results_true.dat
index c9e1bc8fa..0dc1789d4 100644
--- a/tests/regression_tests/dagmc/universes/results_true.dat
+++ b/tests/regression_tests/dagmc/universes/results_true.dat
@@ -1,2 +1,2 @@
k-combined:
-7.687742E-01 3.415061E-02
+9.436168E-01 2.905559E-02
diff --git a/tests/regression_tests/dagmc/universes/test.py b/tests/regression_tests/dagmc/universes/test.py
index 1458462c4..01963986c 100644
--- a/tests/regression_tests/dagmc/universes/test.py
+++ b/tests/regression_tests/dagmc/universes/test.py
@@ -1,3 +1,5 @@
+import numpy as np
+
import openmc
import openmc.lib
@@ -44,16 +46,23 @@ class DAGMCUniverseTest(PyAPITestHarness):
# create the DAGMC universe
pincell_univ = openmc.DAGMCUniverse(filename='dagmc.h5m', auto_geom_ids=True)
- left = openmc.XPlane(x0=-24.0, name='left', boundary_type='reflective')
- right = openmc.XPlane(x0=24.0, name='right', boundary_type='reflective')
- front = openmc.YPlane(y0=-24.0, name='front', boundary_type='reflective')
- back = openmc.YPlane(y0=24.0, name='back', boundary_type='reflective')
- bottom = openmc.ZPlane(z0=-20.0, name='bottom', boundary_type='vacuum')
- top = openmc.ZPlane(z0=20.0, name='top', boundary_type='vacuum')
+ # create a 2 x 2 lattice using the DAGMC pincell
+ pitch = np.asarray((24.0, 24.0))
+ lattice = openmc.RectLattice()
+ lattice.pitch = pitch
+ lattice.universes = [[pincell_univ] * 2] * 2
+ lattice.lower_left = -pitch
- box = +left & -right & +front & -back & +bottom & -top
+ left = openmc.XPlane(x0=-pitch[0], name='left', boundary_type='reflective')
+ right = openmc.XPlane(x0=pitch[0], name='right', boundary_type='reflective')
+ front = openmc.YPlane(y0=-pitch[1], name='front', boundary_type='reflective')
+ back = openmc.YPlane(y0=pitch[1], name='back', boundary_type='reflective')
+ # clip the DAGMC geometry at +/- 10 cm w/ CSG planes
+ bottom = openmc.ZPlane(z0=-10.0, name='bottom', boundary_type='reflective')
+ top = openmc.ZPlane(z0=10.0, name='top', boundary_type='reflective')
- bounding_cell = openmc.Cell(fill=pincell_univ, region=box)
+ bounding_region = +left & -right & +front & -back & +bottom & -top
+ bounding_cell = openmc.Cell(fill=lattice, region=bounding_region)
model.geometry = openmc.Geometry([bounding_cell])