diff --git a/youtube_dl/extractor/common.py b/youtube_dl/extractor/common.py
index cdfa7000b..ae8af61de 100644
--- a/youtube_dl/extractor/common.py
+++ b/youtube_dl/extractor/common.py
@@ -1,3 +1,4 @@
+# coding: utf-8
 from __future__ import unicode_literals
 
 import base64