diff --git a/python/docs/conf.py b/python/docs/conf.py
index d0fd76924..ebb24dbf3 100644
--- a/python/docs/conf.py
+++ b/python/docs/conf.py
@@ -78,7 +78,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = "en"
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.