diff --git a/data_utils/speech.py b/data_utils/speech.py
index 0cea887309d7c443a5dcdb3577ad897e6b36e209..e64109dc8c4e4ce9b7b69c3ccdf75b1fea77300b 100644
--- a/data_utils/speech.py
+++ b/data_utils/speech.py
@@ -3,6 +3,7 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 
+import numpy as np
 from data_utils.audio import AudioSegment