diff --git a/swh/loader/tar/tests/test_utils.py b/swh/loader/tar/tests/test_utils.py
index e2786a0..2b965e9 100644
--- a/swh/loader/tar/tests/test_utils.py
+++ b/swh/loader/tar/tests/test_utils.py
@@ -1,44 +1,43 @@
 # Copyright (C) 2018  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 random
 import unittest
 
 from swh.loader.tar import utils
 
 
 class UtilsLib(unittest.TestCase):
 
     def assert_ok(self, actual_data, expected_data):
         """Check that actual_data and expected_data matched.
 
         Actual data is a random block of data.  We want to check its
         contents match exactly but not the order within.
 
         """
         out = []
         random.shuffle(expected_data)
         for d in actual_data:
             self.assertIn(d, expected_data)
             out.append(d)
         self.assertEqual(len(out), len(expected_data))
 
     def test_random_block(self):
         _input = list(range(0, 9))
         # given
         actual_data = utils.random_blocks(_input, 2)
         self.assert_ok(actual_data, expected_data=_input)
 
     def test_random_block2(self):
         _input = list(range(9, 0, -1))
         # given
         actual_data = utils.random_blocks(_input, 4)
         self.assert_ok(actual_data, expected_data=_input)
 
     def test_random_block_with_fillvalue(self):
         _input = [(i, i+1) for i in range(0, 9)]
-        actual_data = utils.random_blocks(_input, 2,
-                                          fillvalue=(None, None))
+        actual_data = utils.random_blocks(_input, 2)
         self.assert_ok(actual_data, expected_data=_input)
diff --git a/swh/loader/tar/utils.py b/swh/loader/tar/utils.py
index 232832d..2b46989 100644
--- a/swh/loader/tar/utils.py
+++ b/swh/loader/tar/utils.py
@@ -1,37 +1,35 @@
 # Copyright (C) 2015-2018  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 random
 
 from swh.core.utils import grouper
 
 
-def random_blocks(iterable, block=100, fillvalue=None):
-    """Given an iterable:
+def random_blocks(iterable, block=100):
+    """Randomize iterable per block of size block.
+
+    Given an iterable:
 
     - slice the iterable in data set of block-sized elements
     - randomized the block-sized elements
     - yield each element of that randomized block-sized
     - continue onto the next block-sized block
 
     Args:
         iterable (Iterable): an iterable
         block (int): number of elements per block
-        fillvalue (Optional[Something]): value to use as fill-in
-          values (typically for the last loop, the iterable might be
-          less than n elements). None by default but could be anything
-          relevant for the caller (e.g tuple of (None, None))
 
     Yields:
-        random elements per size of block
+        random element of the iterable
 
     """
     count = 0
-    for iter_ in grouper(iterable, block, fillvalue=fillvalue):
+    for iter_ in grouper(iterable, block):
         count += 1
         lst = list(iter_)
         random.shuffle(lst)
         for e in lst:
             yield e