diff --git a/mon-system/monitoring.yaml b/mon-system/monitoring.yaml
index 7faaaa9..fa7f83b 100644
--- a/mon-system/monitoring.yaml
+++ b/mon-system/monitoring.yaml
@@ -302,6 +302,7 @@ data:
       - job_name: 'wan-probe'
         metrics_path: /metrics
         scrape_interval: 30s
+        fallback_scrape_protocol: PrometheusText0.0.4
         static_configs:
           - targets: ['wan-monitor.admin-system:9116']