diff --git a/distiller/quantization/range_linear.py b/distiller/quantization/range_linear.py
index a07c805feeee1a4a6644417d4a7ff45b31537303..343f88712d76578fcaa27563f41b08fce093781a 100644
--- a/distiller/quantization/range_linear.py
+++ b/distiller/quantization/range_linear.py
@@ -22,6 +22,7 @@ from functools import reduce, partial
 import logging
 import os
 from copy import deepcopy
+import warnings
 
 import distiller
 import distiller.utils