diff --git a/setup.cfg b/setup.cfg
index 6897d2c..e165a6d 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -38,6 +38,7 @@ subunit2sql.targets:attach_local = subunit2sql.targets.localdir.AttachmentsDir
 source-dir = doc/source
 build-dir = doc/build
 all_files = 1
+warning-is-error = 1
 
 [upload_sphinx]
 upload-dir = doc/build/html