diff --git a/docs/Manpage.md b/docs/Manpage.md
index 4ee78ea4ec819e..54b71c73600ba1 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -747,6 +747,8 @@ Fetch the newest version of Homebrew and all formulae from GitHub using `git`(1)
 * `-f`, `--force`:
   Always do a slower, full update check (even if unnecessary).
 
+If `HOMEBREW_NO_UPDATE_REPORT_FORMULAE`/`HOMEBREW_NO_UPDATE_REPORT_CASKS` is set, `brew update` will not show the list of newly added formulae/casks respectively
+
 ### `update-reset` [*`path-to-tap-repository`* ...]
 
 Fetch and reset Homebrew and all tap repositories (or any specified *`repository`*) using `git`(1) to their latest `origin/HEAD`.