diff --git a/man/anvil-manage-alerts.8 b/man/anvil-manage-alerts.8
index cb25d87c..b0b47de1 100644
--- a/man/anvil-manage-alerts.8
+++ b/man/anvil-manage-alerts.8
@@ -52,6 +52,8 @@ This is the desired override alert level.
 
 Valid values are: 
 
+0 = "ignore" all alerts
+
 1 = "critical" alerts only
 
 2 = "warning" and critical alerts