--- a/testing/firefox-ui/tests/firefox_ui_tests/puppeteer/test_prefs.py
+++ b/testing/firefox-ui/tests/firefox_ui_tests/puppeteer/test_prefs.py
@@ -44,21 +44,21 @@ class testPreferences(FirefoxTestCase):
 
         # default branch
         orig_value = self.prefs.get_pref(self.int_pref)
         self.prefs.set_pref(self.int_pref, 99999)
         self.assertEqual(self.prefs.get_pref(self.int_pref), 99999)
         self.assertEqual(self.prefs.get_pref(self.int_pref, True), orig_value)
 
         # complex value
-        properties_file = 'chrome://branding/locale/browserconfig.properties'
-        self.assertEqual(self.prefs.get_pref('browser.startup.homepage'),
+        properties_file = 'chrome://browser-region/locale/region.properties'
+        self.assertEqual(self.prefs.get_pref('browser.search.defaultenginename'),
                          properties_file)
 
-        value = self.prefs.get_pref('browser.startup.homepage',
+        value = self.prefs.get_pref('browser.search.defaultenginename',
                                     interface='nsIPrefLocalizedString')
         self.assertNotEqual(value, properties_file)
 
     def test_restore_pref(self):
         # test with single set_pref call and a new preference
         self.prefs.set_pref(self.new_pref, True)
         self.assertTrue(self.prefs.get_pref(self.new_pref))
         self.prefs.restore_pref(self.new_pref)

--- a/testing/puppeteer/firefox/firefox_puppeteer/ui/browser/window.py
+++ b/testing/puppeteer/firefox/firefox_puppeteer/ui/browser/window.py
@@ -28,17 +28,16 @@ class BrowserWindow(BaseWindow):
         'chrome://branding/locale/brand.dtd',
         'chrome://browser/locale/aboutPrivateBrowsing.dtd',
         'chrome://browser/locale/browser.dtd',
         'chrome://browser/locale/netError.dtd',
     ]
 
     properties = [
         'chrome://branding/locale/brand.properties',
-        'chrome://branding/locale/browserconfig.properties',
         'chrome://browser/locale/browser.properties',
         'chrome://browser/locale/preferences/preferences.properties',
         'chrome://global/locale/browser.properties',
     ]
 
     def __init__(self, *args, **kwargs):
         BaseWindow.__init__(self, *args, **kwargs)
 
@@ -49,17 +48,17 @@ class BrowserWindow(BaseWindow):
         self.timeout_page_load = 30
 
     @property
     def default_homepage(self):
         """The default homepage as used by the current locale.
 
         :returns: The default homepage for the current locale.
         """
-        return self._prefs.get_pref('browser.startup.homepage', interface='nsIPrefLocalizedString')
+        return self._prefs.get_pref('browser.startup.homepage')
 
     @property
     def is_private(self):
         """Returns True if this is a Private Browsing window."""
         self.switch_to()
 
         with self.marionette.using_context('chrome'):
             return self.marionette.execute_script("""