diff --git a/test_storage.py b/test_storage.py
index 0ce21cc..bf0850a 100644
--- a/test_storage.py
+++ b/test_storage.py
@@ -1,56 +1,89 @@
 # Copyright (C) 2015  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import shutil
 import tempfile
 import unittest
 
 from nose.tools import istest
 from nose.plugins.attrib import attr
 
 from .db_testing import DbTestFixture
 from swh.core.hashutil import hex_to_hash
 from swh.storage import Storage
 
 
 @attr('db')
 class TestStorage(DbTestFixture, unittest.TestCase):
 
     def setUp(self):
         super().setUp()
         self.objroot = tempfile.mkdtemp()
         self.storage = Storage(self.conn, self.objroot)
 
         self.cont = {
             'data': b'42\n',
             'length': 3,
             'sha1': hex_to_hash(
                 '34973274ccef6ab4dfaaf86599792fa9c3fe4689'),
             'sha1_git': hex_to_hash(
                 'd81cc0710eb6cf9efd5b920a8453e1e07157b6cd'),
             'sha256': hex_to_hash(
                 '673650f936cb3b0a2f93ce09d81be107'
                 '48b1b203c19e8176b4eefc1964a0cf3a'),
         }
 
+        self.cont2 = {
+            'data': b'4242\n',
+            'length': 5,
+            'sha1': hex_to_hash(
+                '61c2b3a30496d329e21af70dd2d7e097046d07b7'),
+            'sha1_git': hex_to_hash(
+                '36fade77193cb6d2bd826161a0979d64c28ab4fa'),
+            'sha256': hex_to_hash(
+                '859f0b154fdb2d630f45e1ecae4a8629'
+                '15435e663248bb8461d914696fc047cd'),
+        }
+
+        self.missing_cont = {
+            'data': b'missing\n',
+            'length': 8,
+            'sha1': hex_to_hash(
+                'f9c24e2abb82063a3ba2c44efd2d3c797f28ac90'),
+            'sha1_git': hex_to_hash(
+                '33e45d56f88993aae6a0198013efa80716fd8919'),
+            'sha256': hex_to_hash(
+                '6bbd052ab054ef222c1c87be60cd191a'
+                'ddedd24cc882d1f5f7f7be61dc61bb3a'),
+        }
+
     def tearDown(self):
         shutil.rmtree(self.objroot)
         super().tearDown()
 
     @istest
     def content_add(self):
         cont = self.cont
 
         self.storage.content_add([cont])
         self.assertIn(cont['sha1'], self.storage.objstorage)
         self.cursor.execute('SELECT sha1, sha1_git, sha256, length, status'
                             ' FROM content WHERE sha1 = %s',
                             (cont['sha1'],))
         datum = self.cursor.fetchone()
         self.assertEqual(
             (datum[0].tobytes(), datum[1].tobytes(), datum[2].tobytes(),
              datum[3], datum[4]),
             (cont['sha1'], cont['sha1_git'], cont['sha256'],
              cont['length'], 'visible'))
+
+    @istest
+    def content_missing(self):
+        cont2 = self.cont2
+        missing_cont = self.missing_cont
+        self.storage.content_add([cont2])
+        gen = self.storage.content_missing([cont2, missing_cont])
+
+        self.assertEqual(list(gen), [missing_cont['sha1']])