--- a/testing/marionette/harness/marionette_harness/tests/unit/test_execute_script.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_execute_script.py
@@ -87,17 +87,28 @@ class TestExecuteContent(MarionetteTestC
         self.assertEqual(
             {"foo": {"bar": [1, 2]}},
             self.marionette.execute_script("return {foo: {bar: [1, 2]}}"))
 
     def test_no_return_value(self):
         self.assertIsNone(self.marionette.execute_script("true"))
 
     def test_argument_null(self):
-        self.assertIsNone(self.marionette.execute_script("return arguments[0]", [None]))
+        self.assertIsNone(self.marionette.execute_script(
+            "return arguments[0]",
+            script_args=(None,),
+            sandbox="default"))
+        self.assertIsNone(self.marionette.execute_script(
+            "return arguments[0]",
+            script_args=(None,),
+            sandbox="system"))
+        self.assertIsNone(self.marionette.execute_script(
+            "return arguments[0]",
+            script_args=(None,),
+            sandbox=None))
 
     def test_argument_number(self):
         self.assertEqual(
             1, self.marionette.execute_script("return arguments[0]", (1,)))
         self.assertEqual(
             1.5, self.marionette.execute_script("return arguments[0]", (1.5,)))
 
     def test_argument_boolean(self):