diff --git a/scripts/upgrade b/scripts/upgrade
index af4d339..39ebbe5 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -47,8 +47,8 @@ if [ -z "$config_path" ]; then
 	ynh_app_setting_set --app=$app --key=final_path --value=$final_path
 fi
 
-# If jellyfin doesn't belong to render group, add it
-if [ ! $(id -Gn $app | grep -q '\brender\b') ]; then
+# If render group exists, and system user doesn't belong to it, add it
+if [ $(grep -q "^render:" /etc/group) ] && [ ! $(id -Gn $app | grep -q '\brender\b') ]; then
 	adduser $app render
 fi