diff --git a/docs/Manpage.md b/docs/Manpage.md
index 3c42e02c71..246599b109 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -1548,14 +1548,16 @@ to send a notification when the autoupdate process has finished successfully.
 <br>Prints the current status of this tool.
 
 `brew autoupdate version`
-<br>Output this tool's current version.
+<br>Output this tool's current version, and a short changelog.
 
 * `--upgrade`:
   Automatically upgrade your installed formulae. If the Caskroom exists locally Casks will be upgraded as well. Must be passed with `start`.
 * `--cleanup`:
   Automatically clean brew's cache and logs. Must be passed with `start`.
 * `--enable-notification`:
-  Send a notification when the autoupdate process has finished successfully, if `terminal-notifier` is installed & found. Note that currently a new experimental notifier runs automatically on macOS Big Sur, without requiring any external dependencies. Must be passed with `start`.
+  Send a notification when the autoupdate process has finished successfully, if `terminal-notifier` is installed & found. Note that currently a new experimental notifier runs automatically on macOS Catalina and newer, without requiring any external dependencies. Must be passed with `start`.
+* `--immediate`:
+  Starts the autoupdate command immediately, instead of waiting for one interval (24 hours by default) to pass first. Must be passed with `start`.
 
 ### `bundle` [*`subcommand`*]
 
diff --git a/manpages/brew.1 b/manpages/brew.1
index 8766af210c..62101dc47b 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -2150,7 +2150,7 @@ This script will run \fBbrew update\fR in the background once every 24 hours (by
 .
 .P
 \fBbrew autoupdate version\fR
-    Output this tool\'s current version\.
+    Output this tool\'s current version, and a short changelog\.
 .
 .TP
 \fB\-\-upgrade\fR
@@ -2162,7 +2162,11 @@ Automatically clean brew\'s cache and logs\. Must be passed with \fBstart\fR\.
 .
 .TP
 \fB\-\-enable\-notification\fR
-Send a notification when the autoupdate process has finished successfully, if \fBterminal\-notifier\fR is installed & found\. Note that currently a new experimental notifier runs automatically on macOS Big Sur, without requiring any external dependencies\. Must be passed with \fBstart\fR\.
+Send a notification when the autoupdate process has finished successfully, if \fBterminal\-notifier\fR is installed & found\. Note that currently a new experimental notifier runs automatically on macOS Catalina and newer, without requiring any external dependencies\. Must be passed with \fBstart\fR\.
+.
+.TP
+\fB\-\-immediate\fR
+Starts the autoupdate command immediately, instead of waiting for one interval (24 hours by default) to pass first\. Must be passed with \fBstart\fR\.
 .
 .SS "\fBbundle\fR [\fIsubcommand\fR]"
 Bundler for non\-Ruby dependencies from Homebrew, Homebrew Cask, Mac App Store and Whalebrew\.