diff --git a/doc/abp.rst b/doc/abp.rst
index 40a4088..1aea327 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: