diff --git a/test_objstorage.py b/test_objstorage.py
new file mode 100644
--- /dev/null
+++ b/test_objstorage.py
@@ -0,0 +1,59 @@
+# 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 os
+import shutil
+import tempfile
+import unittest
+
+from io import BytesIO
+from nose.tools import istest
+
+from swh.storage.objstorage import ObjStorage
+
+
+class Hashlib(unittest.TestCase):
+
+    def setUp(self):
+        self.content = b'42\n'
+        self.obj_id = 'd81cc0710eb6cf9efd5b920a8453e1e07157b6cd'
+        self.obj_steps = ['d8', '1c', 'c0']
+        self.obj_relpath = os.path.join(*(self.obj_steps + [self.obj_id]))
+        self.tmpdir = tempfile.mkdtemp()
+        self.storage = ObjStorage(root=self.tmpdir, depth=3)
+
+    def tearDown(self):
+        shutil.rmtree(self.tmpdir)
+
+    @istest
+    def add_bytes_w_id(self):
+        obj_path = os.path.join(self.tmpdir, self.obj_relpath)
+        self.storage.add_bytes(self.content, obj_id=self.obj_id)
+        self.assertTrue(os.path.isfile(obj_path))
+        self.assertEqual(open(obj_path, 'rb').read(), self.content)
+
+    @istest
+    def add_bytes_wo_id(self):
+        obj_path = os.path.join(self.tmpdir, self.obj_relpath)
+        self.storage.add_bytes(self.content)
+        self.assertTrue(os.path.isfile(obj_path))
+        self.assertEqual(open(obj_path, 'rb').read(), self.content)
+
+    @istest
+    def add_file_w_id(self):
+        obj_path = os.path.join(self.tmpdir, self.obj_relpath)
+        self.storage.add_file(BytesIO(self.content),
+                              len(self.content),
+                              obj_id=self.obj_id)
+        self.assertTrue(os.path.isfile(obj_path))
+        self.assertEqual(open(obj_path, 'rb').read(), self.content)
+
+    @istest
+    def add_file_wo_id(self):
+        obj_path = os.path.join(self.tmpdir, self.obj_relpath)
+        self.storage.add_file(BytesIO(self.content),
+                              len(self.content))
+        self.assertTrue(os.path.isfile(obj_path))
+        self.assertEqual(open(obj_path, 'rb').read(), self.content)