diff --git a/scripts/upgrade b/scripts/upgrade
index a7424c8..79cb1ab 100644
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -192,7 +192,9 @@ ynh_systemd_action --service_name=$app --action="start" --log_path=systemd --lin
 #=================================================
 # We don't test that in CI
 if ! [ ${PACKAGE_CHECK_EXEC:-0} -eq 1 ]; then
-	ynh_add_config --template="nginx.conf" --destination="/etc/nginx/conf.d/$sandboxdomain.d/$app.conf"
+	if [ -n "$sandboxdomain" ]; then
+		ynh_add_config --template="nginx.conf" --destination="/etc/nginx/conf.d/$sandboxdomain.d/$app.conf"
+	fi
 fi
 
 # We authorize access to sandbox domain