diff --git a/docs/operations.md b/docs/operations.md
index c37e093199..81655a3a5c 100644
--- a/docs/operations.md
+++ b/docs/operations.md
@@ -21,6 +21,8 @@ In this situation, the tenant ID is defaulted to be `fake`.
 ### Metrics
 
 Both Loki and promtail expose a `/metrics` endpoint for Prometheus metrics.
+You need add right target info into [prometheus service discovery config](https://prometheus.io/docs/prometheus/latest/configuration/configuration)
+then you can get following metrics.
 
 Loki metrics: