diff --git a/doc/source/index.rst b/doc/source/index.rst
index 182ee72..41fb0ef 100644
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -15,6 +15,7 @@ Contents:
    installation
    usage
    contributing
+   creating_custom_actions
 
 Indices and tables
 ==================
diff --git a/setup.cfg b/setup.cfg
index 571a468..a84d3eb 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -27,6 +27,7 @@ packages =
 source-dir = doc/source
 build-dir = doc/build
 all_files = 1
+warning-is-error = 1
 
 [upload_sphinx]
 upload-dir = doc/build/html