diff --git a/swh/storage/objstorage/objstorage.py b/swh/storage/objstorage/objstorage.py
--- a/swh/storage/objstorage/objstorage.py
+++ b/swh/storage/objstorage/objstorage.py
@@ -4,6 +4,9 @@
 # See top-level LICENSE file for more information
 
 
+ID_HASH_ALGO = 'sha1'
+
+
 class ObjStorage():
     """ High-level API to manipulate the Software Heritage object storage.
 
diff --git a/swh/storage/objstorage/objstorage_pathslicing.py b/swh/storage/objstorage/objstorage_pathslicing.py
--- a/swh/storage/objstorage/objstorage_pathslicing.py
+++ b/swh/storage/objstorage/objstorage_pathslicing.py
@@ -12,12 +12,10 @@
 
 from swh.core import hashutil
 
-from .objstorage import ObjStorage
+from .objstorage import ObjStorage, ID_HASH_ALGO
 from ..exc import ObjNotFoundError, Error
 
 
-ID_HASH_ALGO = 'sha1'
-
 GZIP_BUFSIZ = 1048576
 
 DIR_MODE = 0o755