diff --git a/setup.cfg b/setup.cfg
index 3c2373b..9725260 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -45,6 +45,7 @@ cliff.formatter.completion =
 
 
 [build_sphinx]
-all_files = 1
+all-files = 1
+warning-is-error = 1
 build-dir = doc/build
 source-dir = doc/source