diff --git a/src/state_point.F90 b/src/state_point.F90
index 7991719c84..84a2a18930 100644
--- a/src/state_point.F90
+++ b/src/state_point.F90
@@ -195,7 +195,7 @@ contains
       call close_group(meshes_group)
 
       ! Write information for derivatives.
-      if (size(tally_derivs) > 0) then
+      if (allocated(tally_derivs) .and. size(tally_derivs) > 0) then
         derivs_group = create_group(tallies_group, "derivatives")
         do i = 1, size(tally_derivs)
           associate(deriv => tally_derivs(i))
diff --git a/tests/testing_harness.py b/tests/testing_harness.py
index a462cf1bd3..66cadfe633 100644
--- a/tests/testing_harness.py
+++ b/tests/testing_harness.py
@@ -26,7 +26,7 @@ class TestHarness(object):
         self.parser = OptionParser()
         self.parser.add_option('--exe', dest='exe', default='openmc')
         self.parser.add_option('--mpi_exec', dest='mpi_exec', default=None)
-        self.parser.add_option('--mpi_np', dest='mpi_np', type=int, default=1)
+        self.parser.add_option('--mpi_np', dest='mpi_np', type=int, default=3)
         self.parser.add_option('--update', dest='update', action='store_true',
                                default=False)
         self._opts = None