unattended-upgrades does not upgrade packages from backport

Question

unattended-upgrades works fine, I get daily updates, but once in a while, when I open aptitude, I realize backports packages are not automatically upgraded.

This happens on two different machines (desktop and server), both Debian Jessie.

Anything wrong in my config?

/etc/apt/apt.conf.d/50unattended-upgrades

Unattended-Upgrade::Origins-Pattern {
      "o=Debian,n=jessie";
      "o=Debian,n=jessie-updates";
      "o=Debian,n=jessie-backports";
      "o=Debian,n=jessie-proposed-updates";
      "o=Debian,n=jessie,l=Debian-Security";
};

/etc/apt/sources.list

deb http://ftp.fr.debian.org/debian/ jessie main contrib non-free
deb http://security.debian.org/ jessie/updates main
deb http://ftp.fr.debian.org/debian/ jessie-updates main
deb http://ftp.fr.debian.org/debian/ jessie-backports main

Answer 1

Change the backports entry to

"o=Debian Backports,n=jessie-backports,l=Debian Backports";

BTW, with

unattended-upgrades -v -d

you can see which sources are "allowed" for unattended-upgrades.