diff --git a/datasets/flwr_datasets/partitioner/iid_partitioner.py b/datasets/flwr_datasets/partitioner/iid_partitioner.py
index 37b97468cadf..c8dbf8294fec 100644
--- a/datasets/flwr_datasets/partitioner/iid_partitioner.py
+++ b/datasets/flwr_datasets/partitioner/iid_partitioner.py
@@ -48,5 +48,5 @@ def load_partition(self, idx: int) -> datasets.Dataset:
             single dataset partition
         """
         return self.dataset.shard(
-            num_shards=self._num_partitions, index=idx, contiguous=False
+            num_shards=self._num_partitions, index=idx, contiguous=True
         )
diff --git a/datasets/flwr_datasets/partitioner/iid_partitioner_test.py b/datasets/flwr_datasets/partitioner/iid_partitioner_test.py
index 5f851807f4bd..64c37c4e7127 100644
--- a/datasets/flwr_datasets/partitioner/iid_partitioner_test.py
+++ b/datasets/flwr_datasets/partitioner/iid_partitioner_test.py
@@ -18,7 +18,6 @@
 import unittest
 from typing import Tuple
 
-import numpy as np
 from parameterized import parameterized
 
 from datasets import Dataset
@@ -102,14 +101,15 @@ def test_load_partition_correct_data(
     ) -> None:
         """Test if the data in partition is equal to the expected."""
         dataset, partitioner = _dummy_setup(num_partitions, num_rows)
+        partition_size = num_rows // num_partitions
         partition_index = 2
         partition = partitioner.load_partition(partition_index)
         row_id = 0
         self.assertEqual(
-            partition["features"][row_id],
-            dataset[np.arange(partition_index, len(dataset), num_partitions)][
-                "features"
-            ][row_id],
+            partition[row_id]["features"],
+            # Note it's contiguous so partition_size * partition_index gets the first
+            # element of the partition of partition_index
+            dataset[partition_size * partition_index + row_id]["features"],
         )
 
     @parameterized.expand(  # type: ignore