diff --git a/doc/abp.rst b/doc/abp.rst
index 1aea327..0137109 100644
--- a/doc/abp.rst
+++ b/doc/abp.rst
@@ -36,7 +36,7 @@ abp.clifford module
     :show-inheritance:
 
 abp.nxgraphstate module
--------------------
+-----------------------
 
 .. automodule:: abp.nxgraphstate
     :members: