diff --git a/Create-DevTerm-A04-OS-image-from-scratch.md b/Create-DevTerm-A04-OS-image-from-scratch.md
index b39404f..9bc5d98 100644
--- a/Create-DevTerm-A04-OS-image-from-scratch.md
+++ b/Create-DevTerm-A04-OS-image-from-scratch.md
@@ -27,6 +27,7 @@ so to keep a04 linux kernel in safe , I made devterm-kernel-current-cpi-a04
 
 #  Prepare to chroot into the image 
 ```
+sudo apt install -y qemu-user-static  
 sudo losetup -f # find the avaiable loop device number,eg:loop11
 sudo losetup -P /dev/loop11 ~/build/output/images/Armbian_21.11.0-trunk_Clockworkpi-a04_hirsute_current_5.10.75_xfce_desktop.img 
 sudo mount /dev/loop11p1 /mnt/p1/