diff --git a/doc/source/conf.py b/doc/source/conf.py
index 622483d3..ec4934b9 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # Mistral documentation build configuration file, created by
 # sphinx-quickstart on Fri Nov  1 02:06:28 2013.
 #
diff --git a/releasenotes/source/conf.py b/releasenotes/source/conf.py
index 00ae8a74..aac25ab8 100644
--- a/releasenotes/source/conf.py
+++ b/releasenotes/source/conf.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # Licensed under the Apache License, Version 2.0 (the "License"); you may
 # not use this file except in compliance with the License. You may obtain
 # a copy of the License at