diff --git a/quantize_streaming.py b/quantize_streaming.py
index 0890b66..698faec 100644
--- a/quantize_streaming.py
+++ b/quantize_streaming.py
@@ -4,6 +4,7 @@
 import argparse
 import gc
 import torch
+import concurrent.futures
 from pathlib import Path
 from safetensors.torch import load_file, save_file
 from bitsandbytes.functional import quantize_nf4