diff --git a/cd.sh b/cd.sh
index 4121f9a..1ebbe9e 100644
--- a/cd.sh
+++ b/cd.sh
@@ -4,7 +4,7 @@ NAMESERVERS=(
 REPOSITORY='rwx.work/cd'
 
 echo '
- 1/11 set name servers
+ 1/12 set name servers
 '
 for nameserver in "${NAMESERVERS[@]}" ; do
     echo "nameserver ${nameserver}" \
@@ -13,7 +13,7 @@ for nameserver in "${NAMESERVERS[@]}" ; do
 done
 
 echo '
- 2/11 configure package manager
+ 2/12 configure package manager
 '
 echo -n "\
 Acquire::Check-Valid-Until True;
@@ -24,7 +24,7 @@ Dir::Etc::SourceParts '';
 " > '/etc/apt/apt.conf.d/apt.conf' \
 || exit
 echo '
- 3/11 configure package repositories
+ 3/12 configure package repositories
 '
 echo -n "\
 deb https://deb.debian.org/debian bookworm main
@@ -35,28 +35,28 @@ deb https://deb.debian.org/debian-security bookworm-security main
 || exit
 
 echo '
- 4/11 update package catalog
+ 4/12 update package catalog
 '
 apt-get update \
 || exit
 echo '
- 5/11 install CA certificates package
+ 5/12 install CA certificates package
 '
 apt-get install --yes 'ca-certificates' \
 || exit
 echo '
- 6/11 update package catalog
+ 6/12 update package catalog
 '
 apt-get update \
 || exit
 echo '
- 7/11 upgrade packages
+ 7/12 upgrade packages
 '
 apt-get upgrade --yes \
 || exit
 
 echo '
- 8/11 install Git
+ 8/12 install Git
 '
 apt-get install --yes 'git' \
 || exit
@@ -64,7 +64,7 @@ apt-get install --yes 'git' \
 DIRECTORY="$(mktemp --directory)" \
 || exit
 echo '
- 9/11 clone Continuous Delivery
+ 9/12 clone Continuous Delivery
 '
 git clone \
 "${GITHUB_SERVER_URL}/${REPOSITORY}" \
@@ -72,11 +72,16 @@ git clone \
 || exit
 
 echo '
-10/11 install Python
+10/12 install Python
 '
 apt-get install --yes 'python3' \
 || exit
 echo '
-11/11 bootstrap
+11/12 clean package cache
+'
+apt-get clean \
+|| exit
+echo '
+12/12 bootstrap
 '
 "${DIRECTORY}/bootstrap.sh"