diff --git a/src/calibre/db/tests/base.py b/src/calibre/db/tests/base.py
index 3264465050..8e72721c4e 100644
--- a/src/calibre/db/tests/base.py
+++ b/src/calibre/db/tests/base.py
@@ -7,8 +7,8 @@ __license__   = 'GPL v3'
 __copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
 __docformat__ = 'restructuredtext en'
 
-
 import unittest, os, shutil
+from future_builtins import map
 
 class BaseTest(unittest.TestCase):
 
@@ -39,7 +39,10 @@ class BaseTest(unittest.TestCase):
                 'ondevice_col', 'last_modified'}.union(allfk1)
         for attr in all_keys:
             if attr == 'user_metadata': continue
+            if attr == 'format_metadata': continue # TODO: Not implemented yet
             attr1, attr2 = getattr(mi1, attr), getattr(mi2, attr)
+            if attr == 'formats':
+                attr1, attr2 = map(lambda x:tuple(x) if x else (), (attr1, attr2))
             self.assertEqual(attr1, attr2,
                     '%s not the same: %r != %r'%(attr, attr1, attr2))
             if attr.startswith('#'):