diff --git a/openmc/capi/cell.py b/openmc/capi/cell.py
index ae536e725..959ab08fc 100644
--- a/openmc/capi/cell.py
+++ b/openmc/capi/cell.py
@@ -143,7 +143,7 @@ class Cell(_FortranObjectWithID):
         """
 
         if instance is not None:
-          instance = c_int32(instance)
+            instance = c_int32(instance)
 
         T = c_double()
         _dll.openmc_cell_get_temperature(self._index, instance, T)
@@ -160,7 +160,11 @@ class Cell(_FortranObjectWithID):
             Which instance of the cell
 
         """
-        _dll.openmc_cell_set_temperature(self._index, T, c_int32(instance))
+
+        if instance is not None:
+            instance = c_int32(instance)
+
+        _dll.openmc_cell_set_temperature(self._index, T, instance)
 
 
 class _CellMapping(Mapping):
diff --git a/tests/unit_tests/test_capi.py b/tests/unit_tests/test_capi.py
index be88072d9..07fef8516 100644
--- a/tests/unit_tests/test_capi.py
+++ b/tests/unit_tests/test_capi.py
@@ -75,6 +75,14 @@ def test_cell(capi_init):
     assert str(cell) == 'Cell[0]'
 
 
+def test_cell_temperature(capi_init):
+    cell = openmc.capi.cells[1]
+    cell.set_temperature(100.0, 0)
+    assert cell.get_temperature(0) == 100.0
+    cell.set_temperature(200)
+    assert cell.get_temperature() == 200.0
+
+
 def test_new_cell(capi_init):
     with pytest.raises(exc.AllocationError):
         openmc.capi.Cell(1)