diff --git a/README.md b/README.md
index e2036c6..e0e9a0f 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,7 @@ smartctl_exporter:
   url_path: "/metrics"
   fake_json: no
   smartctl_location: /usr/sbin/smartctl
+  collect_not_more_than_period: 120s
   devices:
   - /dev/sda
   - /dev/sdb