diff --git a/README.md b/README.md
index 4a1d448..c120e63 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,8 @@ This will slightly increase the delay before the application begins responding t
 
 The index can be regenerated at any time by accessing the `/index/rebuild` endpoint.
 
+Automatic index rebuilds can be enabled via the `--index-interval` flag, which accepts [time.Duration](https://pkg.go.dev/time#ParseDuration) strings.
+
 If `--index-file` is set, the index will be loaded from the specified file on start, and written to the file whenever it is re-generated.
 
 The index file consists of (optionally compressed) [gobs](https://pkg.go.dev/encoding/gob).