diff --git a/archive/frames/models.py b/archive/frames/models.py
index bfde369..829ab1c 100644
--- a/archive/frames/models.py
+++ b/archive/frames/models.py
@@ -136,8 +136,8 @@ def get_header_dict(self):
     def as_dict(self):
         ret_dict = model_to_dict(self, exclude=('related_frames', 'area'))
         ret_dict['version_set'] = [v.as_dict() for v in self.version_set.all()]
-        ret_dict['url'] = self.url
-        ret_dict['filename'] = self.filename
+        ret_dict['url'] = self.url if self.version_set.exists() else None
+        ret_dict['filename'] = self.filename if self.version_set.exists() else None
         # TODO: Remove these old model field names once users have migrated their code
         ret_dict['DATE_OBS'] = ret_dict['observation_date']
         ret_dict['DAY_OBS'] = ret_dict['observation_day']
diff --git a/archive/frames/tests/test_views.py b/archive/frames/tests/test_views.py
index a52b5c2..62436ea 100644
--- a/archive/frames/tests/test_views.py
+++ b/archive/frames/tests/test_views.py
@@ -798,11 +798,9 @@ def test_get_thumbnail_list(self):
         self.assertEqual(len(response.json()), 5)
         self.assertContains(response, self.thumbnails[0].filename)
     
-    def test_get_thumbnail_list_filtered(self):
-        response = self.client.get(reverse('thumbnail-list') + '?filename=small')
-        self.assertEqual(len(response.json()), 5)
-        self.assertContains(response, self.thumbnails[0].filename)
-
+    def test_get_thumbnail_list_filtered_by_frame_attribute(self):
+        response = self.client.get(reverse('thumbnail-list') + '?proposal_id=' + self.thumbnails[0].frame.proposal_id)
+        self.assertContains(response, self.thumbnails[0].frame.id)
     
 
 class TestThumbnailPost(ReplicationTestCase):