diff --git a/Doc/reference/index.rst b/Doc/reference/index.rst
index a179d21..18bf053 100644
--- a/Doc/reference/index.rst
+++ b/Doc/reference/index.rst
@@ -17,7 +17,7 @@
 interfaces available to C/C++ programmers in detail.
 
 .. toctree::
-   :maxdepth: 3
+   :maxdepth: 2
 
    introduction.rst
    lexical_analysis.rst