diff --git a/conf/systemd.service b/conf/systemd.service
index 8bb9f42..de343ff 100644
--- a/conf/systemd.service
+++ b/conf/systemd.service
@@ -10,5 +10,35 @@ User=__APP__
 Group=__APP__
 ExecStart=__FINALPATH__/bin/minetestserver --config /home/yunohost.app/__APP__/.minetest/minetest.conf --logfile /var/log/__APP__/__APP__.log
 
+# Sandboxing options to harden security
+# Depending on specificities of your service/app, you may need to tweak these 
+# .. but this should be a good baseline
+# Details for these options: https://www.freedesktop.org/software/systemd/man/systemd.exec.html
+NoNewPrivileges=yes
+PrivateTmp=yes
+PrivateDevices=yes
+RestrictAddressFamilies=AF_UNIX AF_INET AF_INET6
+RestrictNamespaces=yes
+RestrictRealtime=yes
+DevicePolicy=closed
+ProtectSystem=full
+ProtectControlGroups=yes
+ProtectKernelModules=yes
+ProtectKernelTunables=yes
+LockPersonality=yes
+SystemCallFilter=~@clock @debug @module @mount @obsolete @reboot @setuid @swap
+
+# Denying access to capabilities that should not be relevant for webapps
+# Doc: https://man7.org/linux/man-pages/man7/capabilities.7.html
+CapabilityBoundingSet=~CAP_RAWIO CAP_MKNOD
+CapabilityBoundingSet=~CAP_AUDIT_CONTROL CAP_AUDIT_READ CAP_AUDIT_WRITE
+CapabilityBoundingSet=~CAP_SYS_BOOT CAP_SYS_TIME CAP_SYS_MODULE CAP_SYS_PACCT
+CapabilityBoundingSet=~CAP_LEASE CAP_LINUX_IMMUTABLE CAP_IPC_LOCK
+CapabilityBoundingSet=~CAP_BLOCK_SUSPEND CAP_WAKE_ALARM
+CapabilityBoundingSet=~CAP_SYS_TTY_CONFIG
+CapabilityBoundingSet=~CAP_MAC_ADMIN CAP_MAC_OVERRIDE
+CapabilityBoundingSet=~CAP_NET_ADMIN CAP_NET_BROADCAST CAP_NET_RAW
+CapabilityBoundingSet=~CAP_SYS_ADMIN CAP_SYS_PTRACE CAP_SYSLOG 
+
 [Install]
 WantedBy=multi-user.target
diff --git a/scripts/upgrade b/scripts/upgrade
index 7f3e463..315e1c5 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -168,7 +168,9 @@ popd
 # UPDATE A CONFIG FILE
 #=================================================
 ynh_script_progression --message="Updating a configuration file..."
-if [ $is_public -eq 1 ]; then
+
+if ynh_permission_has_user --permission=main --user=visitors
+then
 	announce="true"
 else
 	announce="fase"