diff --git a/source/conf.py b/source/conf.py
index 6f39d52c..ec3e4771 100644
--- a/source/conf.py
+++ b/source/conf.py
@@ -76,7 +76,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = 'en'
+language = "en"
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.