diff --git a/wagtail/tests/settings.py b/wagtail/tests/settings.py
index 4e7eaca6cb..1b4cb8d772 100644
--- a/wagtail/tests/settings.py
+++ b/wagtail/tests/settings.py
@@ -7,6 +7,7 @@ from django.conf import global_settings
 WAGTAIL_ROOT = os.path.dirname(__file__)
 STATIC_ROOT = os.path.join(WAGTAIL_ROOT, 'test-static')
 MEDIA_ROOT = os.path.join(WAGTAIL_ROOT, 'test-media')
+MEDIA_URL = '/media/'
 
 
 DATABASES = {
diff --git a/wagtail/wagtailimages/tests/tests.py b/wagtail/wagtailimages/tests/tests.py
index 8dca205970..652f2c703e 100644
--- a/wagtail/wagtailimages/tests/tests.py
+++ b/wagtail/wagtailimages/tests/tests.py
@@ -140,13 +140,7 @@ class TestFrontendServeView(TestCase):
         response = self.client.get(reverse('wagtailimages_serve', args=(signature, self.image.id, 'fill-800x600')))
 
         # Check response
-        self.assertEqual(response.status_code, 200)
-        self.assertEqual(response['Content-Type'], 'image/jpeg')
-
-        # Make sure the cache headers are set to expire after at least one month
-        self.assertIn('Cache-Control', response)
-        self.assertEqual(response['Cache-Control'].split('=')[0], 'max-age')
-        self.assertTrue(int(response['Cache-Control'].split('=')[1]) > datetime.timedelta(days=30).seconds)
+        self.assertRedirects(response, self.image.renditions.first().url, status_code=301, target_status_code=404)
 
     def test_get_invalid_signature(self):
         """
diff --git a/wagtail/wagtailimages/views/frontend.py b/wagtail/wagtailimages/views/frontend.py
index 0ad2534d36..7c792a1373 100644
--- a/wagtail/wagtailimages/views/frontend.py
+++ b/wagtail/wagtailimages/views/frontend.py
@@ -1,13 +1,11 @@
-from django.shortcuts import get_object_or_404
+from django.shortcuts import get_object_or_404, redirect
 from django.http import HttpResponse
 from django.core.exceptions import PermissionDenied
-from django.views.decorators.cache import cache_control
 
 from wagtail.wagtailimages.models import get_image_model, Filter
 from wagtail.wagtailimages.utils import verify_signature
 
 
-@cache_control(max_age=60*60*24*60) # Cache for 60 days
 def serve(request, signature, image_id, filter_spec):
     image = get_object_or_404(get_image_model(), id=image_id)
 
@@ -15,6 +13,7 @@ def serve(request, signature, image_id, filter_spec):
         raise PermissionDenied
 
     try:
-        return Filter(spec=filter_spec).process_image(image.file.file, HttpResponse(content_type='image/jpeg'), focal_point=image.get_focal_point())
+        rendition = image.get_rendition(filter_spec)
+        return redirect(rendition.url, permanent=True)
     except Filter.InvalidFilterSpecError:
         return HttpResponse("Invalid filter spec: " + filter_spec, content_type='text/plain', status=400)