--- a/testing/marionette/harness/marionette_harness/tests/unit/test_execute_script.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_execute_script.py
@@ -159,20 +159,20 @@ class TestExecuteContent(MarionetteTestC
 
         # by default execute_script pass the name of the python file
         self.assertIn(os.path.basename(__file__.replace(".pyc", ".py")),
                       cm.exception.stacktrace)
         self.assertIn("b is not defined", cm.exception.message)
         self.assertIn("return b", cm.exception.stacktrace)
 
     def test_permission(self):
-        with self.assertRaises(errors.JavascriptException):
-            self.marionette.execute_script("""
-                var c = Components.classes["@mozilla.org/preferences-service;1"];
-            """)
+        for sandbox in ["default", None]:
+            with self.assertRaises(errors.JavascriptException):
+               self.marionette.execute_script(
+                    "Components.classes['@mozilla.org/preferences-service;1']")
 
     def test_return_web_element(self):
         self.marionette.navigate(elements)
         expected = self.marionette.find_element(By.TAG_NAME, "p")
         actual = self.marionette.execute_script(
             "return document.querySelector('p')")
         self.assertEqual(expected, actual)