diff --git a/doc/tutorials/using_ubuntu_as_sos.rst b/doc/tutorials/using_ubuntu_as_sos.rst
index 39aef56f7..471a1651f 100644
--- a/doc/tutorials/using_ubuntu_as_sos.rst
+++ b/doc/tutorials/using_ubuntu_as_sos.rst
@@ -36,7 +36,7 @@ Ubuntu 16.04.4 LTS was used throughout this document, other versions such as
      sudo service ssh start
 
 Install build tools and dependencies
-*************************
+************************************
 
 Install development tools for ARCN development: