diff --git a/bitsandbytes/cuda_setup/main.py b/bitsandbytes/cuda_setup/main.py
index 5f59318..2d14c06 100644
--- a/bitsandbytes/cuda_setup/main.py
+++ b/bitsandbytes/cuda_setup/main.py
@@ -20,6 +20,7 @@ import ctypes as ct
 import os
 import errno
 import torch
+from warnings import warn
 
 from pathlib import Path
 from typing import Set, Union