diff --git a/init.sh b/init.sh
index c5e821e..107f664 100755
--- a/init.sh
+++ b/init.sh
@@ -120,6 +120,12 @@ load_autoconf
 
 load_configuration
 
+# Load pre and post actions for package manager
+for prepost in $MYPATH/prepost/*.sh; do
+    . $prepost
+done
+unset $prepost
+
 process_commandline_and_vars
 
 set_system_proxy
diff --git a/lib/zzz_main_fct.sh b/lib/zzz_main_fct.sh
index 53317b3..d6d5d6e 100644
--- a/lib/zzz_main_fct.sh
+++ b/lib/zzz_main_fct.sh
@@ -153,7 +153,7 @@ chroot_bootstrap()
     fi
 
     local tmpdir=$(mktemp -d $CHROOT_PATH/tmp/init.sh-XXXX)
-    local bootstrap_items="conf lib modules repo bash.rc init.sh"
+    local bootstrap_items="conf lib modules repo bash.rc init.sh prepost.d"
     if [[ $RESUME == true ]]; then
         bootstrap_items="$bootstrap_items $STAGE_FILE"
     fi
diff --git a/prepost.d/ntp.sh b/prepost.d/ntp.sh
new file mode 100644
index 0000000..f003bf9
--- /dev/null
+++ b/prepost.d/ntp.sh
@@ -0,0 +1,21 @@
+# ------------------------------------------------------------------------------
+# NTP package pre and post configuration
+# This file is part of the init.sh project
+# Copyright (c) 2019-2021 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
+# ------------------------------------------------------------------------------
+# This file is distributed under 3-clause BSD license.
+# The complete license agreement can be obtained at:
+# https://opensource.org/licenses/BSD-3-Clause
+# ------------------------------------------------------------------------------
+
+preupgd_ntp()
+{
+    svc_stop ntp
+}
+export -f preupgd_ntp
+
+postupgd_ntp()
+{
+    svc_start ntp
+}
+export -f postupgd_ntp