diff --git a/docs/conf.py b/docs/conf.py
index c1b24a9..46e3e84 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -64,7 +64,7 @@ master_doc = 'index'
 #
 # 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.
diff --git a/docs/requirements.txt b/docs/requirements.txt
index 303f3a6..0ea4ecc 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,3 +1,5 @@
+# ansible_basic_sphinx_ext still imports pkg_resources (removed in setuptools 82+).
+setuptools>=70.0.0,<81.0.0
 antsibull>=0.17.0
 antsibull-docs
 antsibull-changelog