diff --git a/ref/software_guidelines.mdwn b/ref/software_guidelines.mdwn
index b86494b..1b1a400 100644
--- a/ref/software_guidelines.mdwn
+++ b/ref/software_guidelines.mdwn
@@ -21,7 +21,7 @@ the authors. With the requirements and recommendations expressed in
 these guidelines, we intend to facilitate the production and review of
 verifiable and usable software for reproducible research.
 
-[[!toc levels=2]]
+[[!toc levels=3]]
 
 
 \setcounter{secnumdepth}{0}