diff --git a/precise/base-0k/hooks/install.d/30-customize.sh b/precise/base-0k/hooks/install.d/30-customize.sh
index 90f93ab..41eace0 100755
--- a/precise/base-0k/hooks/install.d/30-customize.sh
+++ b/precise/base-0k/hooks/install.d/30-customize.sh
@@ -43,13 +43,12 @@ if ! type -p fzf; then
             case $(lsb_release -rs) in
                 9|9.*)
                     backports_list="/etc/apt/sources.list.d/backports.list"
-                    if ! [ -e "$backports_list" ]; then
-                        echo "deb http://ftp.debian.org/debian stretch-backports main" > \
+                    protect_pre_install /etc/apt/sources.list.d/backports.list
+                    echo "deb http://archive.debian.org/debian stretch-backports main" > \
                              "$backports_list"
-                        ## Update only this repo:
-                        apt-get update -o Dir::Etc::sourcelist="sources.list.d/backports.list" \
-                                -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0"
-                    fi
+                    ## Update only this repo:
+                    apt-get update -o Dir::Etc::sourcelist="sources.list.d/backports.list" \
+                            -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0"
 
                     ;;
             esac