diff --git a/youtube_dlc/heartbeat.py b/youtube_dlc/heartbeat.py
index 7c6a234de..25c0881ed 100644
--- a/youtube_dlc/heartbeat.py
+++ b/youtube_dlc/heartbeat.py
@@ -1,3 +1,6 @@
+# coding: utf-8
+from __future__ import unicode_literals
+
 import time
 import threading
 import traceback