diff --git a/doc/utils/sphinx-config/conf.py.in b/doc/utils/sphinx-config/conf.py.in
index da45dd66a4..c0805ba6b1 100644
--- a/doc/utils/sphinx-config/conf.py.in
+++ b/doc/utils/sphinx-config/conf.py.in
@@ -124,7 +124,7 @@ git_commit = get_git_commit()
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
-#language = None
+language = 'en'
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used: