diff --git a/swh/model/hashutil.py b/swh/model/hashutil.py
index 946edc4a0e252567d3a75614b9686de6ce36e8c2..81c88c3a97688061b3b2390094c2b01dc174ffd6 100644
--- a/swh/model/hashutil.py
+++ b/swh/model/hashutil.py
@@ -7,7 +7,6 @@ import binascii
 import functools
 import hashlib
 import os
-import sys
 
 from io import BytesIO
 
@@ -77,16 +76,11 @@ def _new_hash(algo, length=None):
             raise ValueError('Missing length for git hashing algorithm')
         base_algo = algo[:-4]
         h = _new_git_hash(base_algo, 'blob', length)
-    elif ':' in algo:   # variable length hashing algorithms (only from
-                        # python3 >= 3.6)
-        if sys.version_info.major == 3 and sys.version_info.minor >= 6:
-            _algo = algo.split(':')
-            base_algo = _algo[0]
-            variable_length = int(_algo[1])
-
-            h = hashlib.new('%s%s' % (base_algo, variable_length))
-        else:
-            raise ValueError('Unsupported hashing algorithm %s' % algo)
+    elif ':' in algo:   # variable length hashing algorithms
+        _algo = algo.split(':')
+        base_algo = _algo[0]
+        variable_length = int(_algo[1])
+        h = hashlib.new('%s%s' % (base_algo, variable_length))
     else:
         h = hashlib.new(algo)
 
diff --git a/swh/model/tests/test_hashutil.py b/swh/model/tests/test_hashutil.py
index 435909de8ebbc525b7dd07236c0b260664d94949..8d14524dbbdc842d20e346fb0ca16125c0cf075d 100644
--- a/swh/model/tests/test_hashutil.py
+++ b/swh/model/tests/test_hashutil.py
@@ -8,7 +8,7 @@ import tempfile
 import unittest
 
 from nose.tools import istest
-from unittest.mock import MagicMock, patch
+from unittest.mock import patch
 
 from swh.model import hashutil
 
@@ -131,24 +131,11 @@ class Hashutil(unittest.TestCase):
             hashutil._new_hash('blake2:10')
         except ValueError as e:
             self.assertEquals(str(e),
-                              'Unsupported hashing algorithm blake2:10')
+                              'unsupported hash type blake210')
 
-    @patch('swh.model.hashutil.sys')
-    @istest
-    def new_hash_unexpected_hashing_algo(self, mock_sys):
-        mock_sys.version_info = MagicMock(major=3, minor=6)
-
-        try:
-            hashutil._new_hash('blake3:256')
-        except ValueError as e:
-            self.assertEquals(str(e),
-                              'unsupported hash type blake3256')
-
-    @patch('swh.model.hashutil.sys')
     @patch('swh.model.hashutil.hashlib')
     @istest
-    def new_hash_blake2b(self, mock_hashlib, mock_sys):
-        mock_sys.version_info = MagicMock(major=3, minor=6)
+    def new_hash_blake2b(self, mock_hashlib):
         mock_hashlib.new.return_value = 'some-hashlib-object'
 
         h = hashutil._new_hash('blake2b:512')
@@ -156,17 +143,14 @@ class Hashutil(unittest.TestCase):
         self.assertEquals(h, 'some-hashlib-object')
         mock_hashlib.new.assert_called_with('blake2b512')
 
-    @patch('swh.model.hashutil.sys')
     @patch('swh.model.hashutil.hashlib')
     @istest
-    def new_hash_blake2s(self, mock_hashlib, mock_sys):
-        mock_sys.version_info = MagicMock(major=3, minor=6)
+    def new_hash_blake2s(self, mock_hashlib):
         mock_hashlib.new.return_value = 'some-hashlib-object'
 
         h = hashutil._new_hash('blake2s:256')
 
         self.assertEquals(h, 'some-hashlib-object')
-        mock_hashlib.blake2s.assert_called_with(digest_size=128)
         mock_hashlib.new.assert_called_with('blake2s256')