diff --git a/torchstore/utils.py b/torchstore/utils.py
index 5536bde..bbc8109 100644
--- a/torchstore/utils.py
+++ b/torchstore/utils.py
@@ -4,12 +4,11 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
+import math
 import uuid
 from logging import getLogger
 from typing import List, Tuple, TYPE_CHECKING
 
-import numpy as np
-
 import torch
 
 from torchstore.constants import MONARCH_HOSTMESH_V1
@@ -119,8 +118,8 @@ def get_target_tensor_shape_and_offset(
 
     # Verify that local tensors can fill the target tensor, this verification is only necessary but not
     # sufficient to guarantee that the target tensor can be filled by local tensors.
-    local_tensor_total_size = sum([np.prod(shape) for shape in local_tensor_shapes])
-    target_tensor_size = np.prod(target_shape)
+    local_tensor_total_size = sum([math.prod(shape) for shape in local_tensor_shapes])
+    target_tensor_size = math.prod(target_shape)
     assert (
         local_tensor_total_size >= target_tensor_size
     ), "Local tensor sizes doesn't match target tensor. "