diff -r 6eeb7abda47a -r baed516c6f6e cubicweb/server/test/unittest_migractions.py
--- a/cubicweb/server/test/unittest_migractions.py	Fri Jun 10 13:23:54 2016 +0200
+++ b/cubicweb/server/test/unittest_migractions.py	Fri Jun 10 16:45:20 2016 +0200
@@ -773,7 +773,8 @@
             self.assertEqual(len(bffss_dir_content), 1)
             john.cw_clear_all_caches()
             self.assertEqual(john.photo.getvalue(),
-                             osp.join(tempfile.tempdir, bffss_dir_content[0]))
+                             osp.join(tempfile.tempdir,
+                                      bffss_dir_content[0]).encode('utf8'))
             bob.cw_clear_all_caches()
             self.assertIsNone(bob.photo)
             bill.cw_clear_all_caches()