diff --git a/doc/conf.py b/doc/conf.py
index 8070ed40ca0dfda88b50776cae71ee7536f90fae..dc14cece4e252082a9900a5c84a2fc9c7f3c21b9 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # -- Project information -----------------------------------------------------
 
 project = u'psrdada-cpp'