diff --git a/swh/objstorage/__init__.py b/swh/objstorage/__init__.py
index 594bd07..bc4dd77 100644
--- a/swh/objstorage/__init__.py
+++ b/swh/objstorage/__init__.py
@@ -1,65 +1,67 @@
 # Copyright (C) 2016  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
 
 from .objstorage import ObjStorage
 from .objstorage_pathslicing import PathSlicingObjStorage
+from .objstorage_in_memory import InMemoryObjStorage
 from .api.client import RemoteObjStorage
 from .multiplexer import MultiplexerObjStorage
 from .multiplexer.filter import add_filters
 
 
 __all__ = ['get_objstorage', 'ObjStorage']
 
 
 _STORAGE_CLASSES = {
     'pathslicing': PathSlicingObjStorage,
     'remote': RemoteObjStorage,
+    'in-memory': InMemoryObjStorage,
 }
 
 try:
     from swh.objstorage.cloud.objstorage_azure import AzureCloudObjStorage
     _STORAGE_CLASSES['azure-storage'] = AzureCloudObjStorage
 except ImportError:
     pass
 
 
 def get_objstorage(cls, args):
     """ Create an ObjStorage using the given implementation class.
 
     Args:
         cls (str): objstorage class unique key contained in the
             _STORAGE_CLASSES dict.
         args (dict): arguments for the required class of objstorage
             that must match exactly the one in the `__init__` method of the
             class.
     Returns:
         subclass of ObjStorage that match the given `storage_class` argument.
     Raises:
         ValueError: if the given storage class is not a valid objstorage
             key.
     """
     try:
         return _STORAGE_CLASSES[cls](**args)
     except KeyError:
         raise ValueError('Storage class %s does not exist' % cls)
 
 
 def _construct_filtered_objstorage(storage_conf, filters_conf):
     return add_filters(
         get_objstorage(**storage_conf),
         filters_conf
     )
 
 
 _STORAGE_CLASSES['filtered'] = _construct_filtered_objstorage
 
 
 def _construct_multiplexer_objstorage(objstorages):
     storages = [get_objstorage(**conf)
                 for conf in objstorages]
     return MultiplexerObjStorage(storages)
 
 
 _STORAGE_CLASSES['multiplexer'] = _construct_multiplexer_objstorage
diff --git a/swh/objstorage/objstorage_in_memory.py b/swh/objstorage/objstorage_in_memory.py
new file mode 100644
index 0000000..c023744
--- /dev/null
+++ b/swh/objstorage/objstorage_in_memory.py
@@ -0,0 +1,55 @@
+# Copyright (C) 2017  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
+
+from swh.objstorage.exc import ObjNotFoundError
+from swh.objstorage import objstorage
+
+
+class InMemoryObjStorage(objstorage.ObjStorage):
+    """In-Memory objstorage.
+
+    Intended for test purposes.
+
+    """
+    state = {}
+
+    def __init__(self, **args):
+        super().__init__()
+
+    def check_config(self, *, check_write):
+        return True
+
+    def __contains__(self, obj_id, *args, **kwargs):
+        return obj_id in self.state
+
+    def add(self, content, obj_id=None, check_presence=True, *args, **kwargs):
+        if obj_id is None:
+            obj_id = objstorage.compute_hash(content)
+
+        if check_presence and obj_id in self:
+            return obj_id
+
+        self.state[obj_id] = content
+
+        return obj_id
+
+    def get(self, obj_id, *args, **kwargs):
+        if obj_id not in self:
+            raise ObjNotFoundError(obj_id)
+
+        return self.state[obj_id]
+
+    def check(self, obj_id, *args, **kwargs):
+        if obj_id not in self:
+            raise ObjNotFoundError(obj_id)
+        return True
+
+    def delete(self, obj_id, *args, **kwargs):
+        super().delete(obj_id)  # Check delete permission
+        if obj_id not in self:
+            raise ObjNotFoundError(obj_id)
+
+        self.state.pop(obj_id)
+        return True
diff --git a/swh/objstorage/tests/test_objstorage_in_memory.py b/swh/objstorage/tests/test_objstorage_in_memory.py
new file mode 100644
index 0000000..ca90422
--- /dev/null
+++ b/swh/objstorage/tests/test_objstorage_in_memory.py
@@ -0,0 +1,16 @@
+# Copyright (C) 2015-2016  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 unittest
+
+from swh.objstorage.objstorage_in_memory import InMemoryObjStorage
+
+from objstorage_testing import ObjStorageTestFixture
+
+
+class TestMultiplexerObjStorage(ObjStorageTestFixture, unittest.TestCase):
+    def setUp(self):
+        super().setUp()
+        self.storage = InMemoryObjStorage()