diff --git a/README.md b/README.md
index ff1058d6..460cf3ff 100644
--- a/README.md
+++ b/README.md
@@ -201,6 +201,8 @@ Start your prometheus like this, for example:
 
 > Note: make sure to have a valid `prometheus.yml` in your current directory
 
+> Important: Do not load balance traffic between Prometheus and its Alertmanagers, but instead point Prometheus to a list of all Alertmanagers. The Alertmanager implementation expects all alerts to be sent to all Alertmanagers to ensure high availability.
+
 ## Architecture
 
 ![](https://raw.githubusercontent.com/prometheus/alertmanager/4e6695682acd2580773a904e4aa2e3b927ee27b7/doc/arch.jpg)