diff --git a/System-Metrics.md b/System-Metrics.md
index 756b0a1..eb1bbdc 100644
--- a/System-Metrics.md
+++ b/System-Metrics.md
@@ -32,10 +32,11 @@ SeaweedFS can also start with ports accepting Prometheus metrics queries.
 
 ```
 weed server -metricsPort=1234
-weed master -metricsPort=1234
-weed volume -metricsPort=1234
-weed filer  -metricsPort=1234
+weed master -metricsPort=1235
+weed volume -metricsPort=1236
+weed filer  -metricsPort=1237
 ```
+Note: All server should be running on different ports for accepting prometheus metrics queries.
 
 And then you can configure your Prometheus to crawl them periodically.