diff --git a/README.md b/README.md
index 618acc0..a81b55d 100644
--- a/README.md
+++ b/README.md
@@ -296,7 +296,7 @@ To get you started, here's a rule that will trigger an alert if there are any no
 ```yaml
 alert: goldpinger_nodes_unhealthy
 expr: sum(goldpinger_nodes_health_total{status="unhealthy"})
-  BY (goldpinger_instance) > 0
+  BY (instance, goldpinger_instance) > 0
 for: 5m
 annotations:
   description: |