diff --git a/django/views/i18n.py b/django/views/i18n.py
index 5cb59c3262..831a764a2a 100644
--- a/django/views/i18n.py
+++ b/django/views/i18n.py
@@ -219,7 +219,7 @@ def javascript_catalog(request, domain='djangojs', packages=None):
                 except IOError:
                     catalog = None
                 if catalog is not None:
-                    t.update(catalog._catalog)
+                    t = catalog._catalog
     src = [LibHead]
     plural = None
     if '' in t:
diff --git a/tests/regressiontests/admin_views/tests.py b/tests/regressiontests/admin_views/tests.py
index abb28de38b..c676555fa7 100644
--- a/tests/regressiontests/admin_views/tests.py
+++ b/tests/regressiontests/admin_views/tests.py
@@ -2,6 +2,7 @@
 
 import re
 import datetime
+from django.conf import settings
 from django.core.files import temp as tempfile
 from django.test import TestCase
 from django.contrib.auth import admin # Register auth models with the admin.
@@ -15,7 +16,7 @@ from django.forms.util import ErrorList
 from django.utils import formats
 from django.utils.cache import get_max_age
 from django.utils.html import escape
-from django.utils.translation import get_date_formats
+from django.utils.translation import get_date_formats, activate, deactivate
 from django.utils.encoding import iri_to_uri
 
 # local test models
@@ -271,6 +272,34 @@ class AdminViewBasicTest(TestCase):
         response = self.client.get("/test_admin/admin/admin_views/post/")
         self.failUnless('icon-unknown.gif' in response.content)
 
+    def testI18NLanguageNonEnglishDefault(self):
+        """
+        Check if the Javascript i18n view returns an empty language catalog
+        if the default language is non-English but the selected language
+        is English. See #13388 and #3594 for more details.
+        """
+        old_language_code = settings.LANGUAGE_CODE
+        settings.LANGUAGE_CODE = 'fr'
+        activate('en-us')
+        response = self.client.get('/test_admin/admin/jsi18n/')
+        self.assertNotContains(response, 'Choisir une heure')
+        deactivate()
+        settings.LANGUAGE_CODE = old_language_code
+
+    def testI18NLanguageNonEnglishFallback(self):
+        """
+        Makes sure that the fallback language is still working properly
+        in cases where the selected language cannot be found.
+        """
+        old_language_code = settings.LANGUAGE_CODE
+        settings.LANGUAGE_CODE = 'fr'
+        activate('none')
+        response = self.client.get('/test_admin/admin/jsi18n/')
+        self.assertContains(response, 'Choisir une heure')
+        deactivate()
+        settings.LANGUAGE_CODE = old_language_code
+
+
 class SaveAsTests(TestCase):
     fixtures = ['admin-views-users.xml','admin-views-person.xml']
 
@@ -1945,7 +1974,7 @@ class NeverCacheTests(TestCase):
 
     def testJsi18n(self):
         "Check the never-cache status of the Javascript i18n view"
-        response = self.client.get('/test_admin/jsi18n/')
+        response = self.client.get('/test_admin/admin/jsi18n/')
         self.failUnlessEqual(get_max_age(response), None)