diff --git a/usbboot/Readme.md b/usbboot/Readme.md
index 580b40f0b..9c0c7f672 100644
--- a/usbboot/Readme.md
+++ b/usbboot/Readme.md
@@ -46,6 +46,7 @@ git clone git://git.buildroot.net/buildroot
 ```
 cd buildroot
 patch -p1 < ../tools/usbboot/buildroot.patch
+chmod +x board/raspberrypi/usb_test/post_build.sh
 make raspberrypi_defconfig
 make
 ```