diff --git a/cluster/apt.apply.update.sh b/cluster/apt.apply.update.sh
index d8a5cf9..5ff8c7e 100755
--- a/cluster/apt.apply.update.sh
+++ b/cluster/apt.apply.update.sh
@@ -5,7 +5,7 @@
 #   2. No SGE jobs are running
 #   3. No process related to Maco are running
 
-# This script can be call by a cronjob (eg. hourly)
+# This script can be called by a cronjob (eg. hourly)
 
 # Vars {{{
 readonly PROGNAME=$(basename "${0}")
@@ -260,6 +260,15 @@ procs running (with the pattern: ${RED}${local_proc_pattern}${COLOR_DEBUG}) on t
 
 	return "${return_proc_running}"
 
+}
+# }}}
+prepare_host() {                                              # {{{
+
+	debug_message "prepare_host − \
+Forbid SSH logins,…".
+
+	touch /etc/nologin
+
 }
 # }}}
 upgrade_system() {                                              # {{{
@@ -277,7 +286,7 @@ clean_host() {                                                  # {{{
 Try to clean temp files, downloaded packages,…".
 
 	aptitude clean >> "${APT_TMP_FILE}" 2>&1 \
-	&& rm -f -- "${APT_TMP_FILE}"
+	&& rm -f -- "${APT_TMP_FILE}" /etc/nologin
 
 }
 # }}}
@@ -312,6 +321,9 @@ main() {                                                        # {{{
 	is_proc_running "${maco_proc_pattern}" \
 		&& exit 0
 
+	## Prepare the host for upgrade
+	prepare_host
+
 	## Try to upgrade the system
 	### If error: Exit 50
 	### If success: Clean host (temp files, download,…)