diff --git a/Create-devterm-cm3-os-image-from-scratch.md b/Create-devterm-cm3-os-image-from-scratch.md
index 6c50054..c946d8b 100644
--- a/Create-devterm-cm3-os-image-from-scratch.md
+++ b/Create-devterm-cm3-os-image-from-scratch.md
@@ -4,6 +4,7 @@ and it is better to run a Ubuntu 21.04 in a VirtualBox to do all the jobs
 The entire operation requires a certain experience in linux  
 be careful  
 
+## Start a chroot env
 ```
 wget https://downloads.raspberrypi.org/raspios_full_armhf/images/raspios_full_armhf-2021-05-28/2021-05-07-raspios-buster-armhf-full.zip