diff --git a/swh/model/hashutil.py b/swh/model/hashutil.py
index 0e789834a4e18eba2b0be6040ac4d74a9294cadf..06579bd3c64f533b4b1ebd532d7ab5b51937ef9d 100644
--- a/swh/model/hashutil.py
+++ b/swh/model/hashutil.py
@@ -45,14 +45,6 @@ HASH_BLOCK_SIZE = 32768
 
 _blake2_hash_cache = {}
 
-HASH_FORMATS = set(['bytes', 'bytehex', 'hex'])
-"""Supported output hash formats
-"""
-
-EXTRA_LENGTH = set(['length'])
-"""Extra information to compute
-"""
-
 
 class MultiHash:
     """Hashutil class to support multiple hashes computation.