diff --git a/boards/tests/test_sync.py b/boards/tests/test_sync.py
--- a/boards/tests/test_sync.py
+++ b/boards/tests/test_sync.py
@@ -15,7 +15,7 @@ class SyncTest(TestCase):
         Forms a GET request of a post and checks the response.
         """
 
-        KeyPair.objects.generate_key(primary=True)
+        key = KeyPair.objects.generate_key(primary=True)
         tag = Tag.objects.create(name='tag1')
         post = Post.objects.create_post(title='test_title', text='test_text',
                                         tags=[tag])
@@ -44,16 +44,19 @@ class SyncTest(TestCase):
             '<pub-time>%s</pub-time>'
             '</content>' % (
                 post.global_id.key,
-                post.id,
+                post.global_id.local_id,
                 post.global_id.key_type,
                 post.title,
                 post.get_raw_text(),
                 post.get_thread().get_tags().first().name,
                 post.get_pub_time_str(),
-            ) in response_get(request).content.decode(),
+            ) in response,
             'Wrong response generated for the GET request.')
 
         post.delete()
+        key.delete()
+
+        KeyPair.objects.generate_key(primary=True)
 
         SyncManager.parse_response_get(response)
         self.assertEqual(1, Post.objects.count(),
@@ -70,3 +73,29 @@ class SyncTest(TestCase):
 
         self.assertEqual(1, parsed_post.global_id.signature_set.count(),
                          'Signature was not saved.')
+
+        post = parsed_post
+
+        # Trying to sync the same once more
+        response = response_get(request).content.decode()
+
+        self.assertTrue(
+            '<status>success</status>'
+            '<models>'
+            '<model name="post">'
+            '<content>'
+            '<id key="%s" local-id="%d" type="%s" />'
+            '<title>%s</title>'
+            '<text>%s</text>'
+            '<tags><tag>%s</tag></tags>'
+            '<pub-time>%s</pub-time>'
+            '</content>' % (
+                post.global_id.key,
+                post.global_id.local_id,
+                post.global_id.key_type,
+                post.title,
+                post.get_raw_text(),
+                post.get_thread().get_tags().first().name,
+                post.get_pub_time_str(),
+            ) in response,
+            'Wrong response generated for the GET request.')