diff --git a/tests/regression_tests/cpp_driver/driver.cpp b/tests/regression_tests/cpp_driver/driver.cpp
index 2bc771b24..87d5ca9f5 100644
--- a/tests/regression_tests/cpp_driver/driver.cpp
+++ b/tests/regression_tests/cpp_driver/driver.cpp
@@ -1,6 +1,8 @@
 
 #include "openmc/capi.h"
 #include "openmc/cell.h"
+#include "openmc/geometry.h"
+#include "openmc/summary.h"
 #include "openmc/tallies/filter.h"
 #include "openmc/tallies/filter_cell.h"
 #include "openmc/tallies/tally.h"
@@ -29,6 +31,17 @@ int main(int argc, char** argv) {
   tally->set_filters(filters);
   tally->set_scores({"flux"});
 
+  // set the temperature of the cell containing
+  // the lattice
+  auto& root_univ = openmc::model::universes[openmc::model::root_universe];
+  auto& lattice_cell = openmc::model::cells[root_univ->cells_[0]];
+  lattice_cell->set_temperature(300, 1, true);
+
+  // the summary file will be used to check that
+  // temperatures were set correctly so clear
+  // error output can be provided
+  openmc::write_summary();
+
   openmc_run();
   openmc_finalize();
   return 0;
diff --git a/tests/regression_tests/cpp_driver/inputs_true.dat b/tests/regression_tests/cpp_driver/inputs_true.dat
index 4d0e90d8f..84efa6467 100644
--- a/tests/regression_tests/cpp_driver/inputs_true.dat
+++ b/tests/regression_tests/cpp_driver/inputs_true.dat
@@ -2,8 +2,22 @@
 <geometry>
   <cell id="1" material="1" region="-1" universe="1" />
   <cell id="2" material="2" region="1 -2" universe="1" />
+  <cell id="3" material="3" region="2" universe="1" />
+  <cell fill="2" id="4" region="3 -4 5 -6" universe="3" />
+  <lattice id="2">
+    <pitch>4.0 4.0</pitch>
+    <dimension>2 2</dimension>
+    <lower_left>-4.0 -4.0</lower_left>
+    <universes>
+1 1 
+1 1 </universes>
+  </lattice>
   <surface coeffs="0.0 0.0 1.5" id="1" type="z-cylinder" />
-  <surface boundary="reflective" coeffs="0.0 0.0 3.0" id="2" type="z-cylinder" />
+  <surface coeffs="0.0 0.0 1.7" id="2" type="z-cylinder" />
+  <surface boundary="reflective" coeffs="-4.0" id="3" name="minimum x" type="x-plane" />
+  <surface boundary="reflective" coeffs="4.0" id="4" name="maximum x" type="x-plane" />
+  <surface boundary="reflective" coeffs="-4.0" id="5" name="minimum y" type="y-plane" />
+  <surface boundary="reflective" coeffs="4.0" id="6" name="maximum y" type="y-plane" />
 </geometry>
 <?xml version='1.0' encoding='utf-8'?>
 <materials>
@@ -11,7 +25,11 @@
     <density units="g/cc" value="11" />
     <nuclide ao="1.0" name="U235" />
   </material>
-  <material id="2" name="water">
+  <material id="2" name="cladding">
+    <density units="g/cc" value="6.44" />
+    <nuclide ao="1.0" name="Zr90" />
+  </material>
+  <material id="3" name="water">
     <density units="g/cc" value="1.0" />
     <nuclide ao="2.0" name="H1" />
     <nuclide ao="1.0" name="O16" />
diff --git a/tests/regression_tests/cpp_driver/results_true.dat b/tests/regression_tests/cpp_driver/results_true.dat
index 7748cf5c0..77de290ce 100644
--- a/tests/regression_tests/cpp_driver/results_true.dat
+++ b/tests/regression_tests/cpp_driver/results_true.dat
@@ -1,7 +1,11 @@
 k-combined:
-1.857752E+00 2.922425E-02
+1.934690E+00 2.593158E-02
 tally 1:
-5.337194E+01
-3.209877E+02
-1.621671E+02
-2.939588E+03
+8.771138E+01
+8.618680E+02
+2.643695E+01
+7.811923E+01
+8.917373E+01
+8.880318E+02
+2.033221E+02
+4.619301E+03
diff --git a/tests/regression_tests/cpp_driver/test.py b/tests/regression_tests/cpp_driver/test.py
index a4dd8785b..42f0c2e58 100644
--- a/tests/regression_tests/cpp_driver/test.py
+++ b/tests/regression_tests/cpp_driver/test.py
@@ -4,6 +4,7 @@ import shutil
 import subprocess
 import textwrap
 
+from numpy.testing import assert_allclose
 import openmc
 import pytest
 
@@ -46,6 +47,7 @@ def cpp_driver(request):
     finally:
         # Remove local build directory when test is complete
         shutil.rmtree('build')
+        os.remove('CMakeLists.txt')
 
 
 @pytest.fixture
@@ -57,22 +59,39 @@ def model():
     u235.add_nuclide('U235', 1.0, 'ao')
     u235.set_density('g/cc', 11)
 
+    zirc = openmc.Material(name='cladding')
+    zirc.add_nuclide('Zr90', 1.0)
+    zirc.set_density('g/cc', 6.44)
+
     water = openmc.Material(name="water")
     water.add_nuclide('H1', 2.0, 'ao')
     water.add_nuclide('O16', 1.0, 'ao')
     water.set_density('g/cc', 1.0)
 
-    mats = openmc.Materials([u235, water])
+    mats = openmc.Materials([u235, zirc, water])
     model.materials = mats
 
     # geometry
     fuel_or = openmc.ZCylinder(r=1.5)
-    coolant_or = openmc.ZCylinder(r=3.0, boundary_type='reflective')
+    cladding_or = openmc.ZCylinder(r=1.7)
 
     fuel = openmc.Cell(fill=u235, region=-fuel_or)
-    coolant = openmc.Cell(fill=water, region=+fuel_or & -coolant_or)
+    cladding = openmc.Cell(fill=zirc, region=+fuel_or & -cladding_or)
+    moderator = openmc.Cell(fill=water, region=+cladding_or)
 
-    model.geometry = openmc.Geometry([fuel, coolant])
+    pincell_univ = openmc.Universe(cells=[fuel, cladding, moderator])
+
+    # lattice
+    lattice = openmc.RectLattice()
+    lattice.pitch = (4.0, 4.0)
+    lattice.lower_left = (-4.0, -4.0)
+    lattice.universes = [[pincell_univ, pincell_univ], [pincell_univ, pincell_univ]]
+    lattice_region = openmc.model.rectangular_prism(8.0,
+                                                    8.0,
+                                                    boundary_type='reflective')
+    lattice_cell = openmc.Cell(fill=lattice, region=lattice_region)
+
+    model.geometry = openmc.Geometry([lattice_cell])
 
     model.settings.particles = 100
     model.settings.batches = 10
@@ -97,6 +116,22 @@ class ExternalDriverTestHarness(PyAPITestHarness):
             openmc.run(openmc_exec=self.executable,
                        event_based=config['event'])
 
+    def _compare_results(self):
+        super()._compare_results()
+
+        # load the summary file
+        summary = openmc.Summary('summary.h5')
+
+        # get the summary cells
+        cells = summary.geometry.get_all_cells()
+
+        # for the 2 by 2 lattice, each cell should have 4
+        # temperature values set to 300 K
+        for cell in cells.values():
+            if isinstance(cell.fill, openmc.Material):
+                assert len(cell.temperature) == 4
+                assert_allclose(cell.temperature, 300.0)
+
 
 def test_cpp_driver(cpp_driver, model):
     harness = ExternalDriverTestHarness(cpp_driver, 'statepoint.10.h5', model)
diff --git a/tests/regression_tests/source_dlopen/test.py b/tests/regression_tests/source_dlopen/test.py
index 12969cf29..41690224d 100644
--- a/tests/regression_tests/source_dlopen/test.py
+++ b/tests/regression_tests/source_dlopen/test.py
@@ -39,6 +39,7 @@ def compile_source(request):
 
     # Remove local build directory when test is complete
     shutil.rmtree('build')
+    os.remove('CMakeLists.txt')
 
 
 @pytest.fixture