--- /dev/null
+#!/bin/sh
+#SPDX-License-Identifier: GPL-3.0-or-later
+#Please see the full text of the license under /usr/share/common-licenses.
+set -e
+
+#The Planet APT repository is obsolete and should not be used. This deletes it.
+find /etc/apt/sources.list* -type f -exec sed -i '/linux-libre.fsfla.org\/pub\/linux-libre\/planet/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.cedia.org.ec\/linux-libre\/planet/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.cyberbits.eu\/linux-libre\/planet/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/linux-libre.gnulinux.si\/planet/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/ftp.linux.org.tr\/linux-libre\/planet/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.splentity.com\/linux-libre\/planet/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.linux.pizza\/linux-libre\/planet/d' {} \;
+
+#Everyone is moving to the deb822 format; this removes older entries that are no longer needed.
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.cedia.org.ec\/linux-libre\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.cyberbits.eu\/linux-libre\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/linux-libre.fsfla.org\/pub\/linux-libre\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/linux-libre.gnulinux.si\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/ftp.linux.org.tr\/linux-libre\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.linux.pizza\/linux-libre\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/linuxliber.md\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/linuxliber.ro\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.splentity.com\/liberty/d' {} \;
+find /etc/apt/sources.list* -type f -exec sed -i '/mirror.uta.edu.ec\/linux-libre\/liberty/d' {} \;