--- a/testing/marionette/harness/marionette_harness/tests/unit/test_import_script.py
+++ b/testing/marionette/harness/marionette_harness/tests/unit/test_import_script.py
@@ -2,17 +2,22 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import os
 
 from marionette_driver.by import By
 from marionette_driver.errors import JavascriptException
 
-from marionette_harness import MarionetteTestCase, WindowManagerMixin, skip_if_chrome
+from marionette_harness import (
+    MarionetteTestCase,
+    skip_if_chrome,
+    skip_if_mobile,
+    WindowManagerMixin,
+)
 
 
 class TestImportScriptContent(WindowManagerMixin, MarionetteTestCase):
     contexts = set(["chrome", "content"])
 
     script_file = os.path.abspath(
         os.path.join(__file__, os.path.pardir, "importscript.js"))
     another_script_file = os.path.abspath(
@@ -100,16 +105,17 @@ class TestImportScriptContent(WindowMana
 
     def test_multiple_imports(self):
         self.marionette.import_script(self.script_file)
         self.marionette.import_script(self.another_script_file)
         self.assert_defined("testFunc")
         self.assert_defined("testAnotherFunc")
 
     @skip_if_chrome
+    @skip_if_mobile  # New windows not supported in Fennec
     def test_imports_apply_globally(self):
         self.marionette.navigate(
             self.marionette.absolute_url("test_windows.html"))
 
         def open_window_with_link():
             self.marionette.find_element(By.LINK_TEXT, "Open new window").click()
 
         new_window = self.open_window(trigger=open_window_with_link)