diff --git a/Documentation/sound/index.rst b/Documentation/sound/index.rst
index 280a571..e9bac7c 100644
--- a/Documentation/sound/index.rst
+++ b/Documentation/sound/index.rst
@@ -6,6 +6,7 @@
    :maxdepth: 2
 
    kernel-api/index
+   hd-audio/index
 
 .. only::  subproject