diff --git a/app/asr_engine.py b/app/asr_engine.py
index 1302b57..959f5c0 100644
--- a/app/asr_engine.py
+++ b/app/asr_engine.py
@@ -1,3 +1,4 @@
+import os
 from traceback import print_exc
 import base64
 import wave