diff --git a/docs/Manpage.md b/docs/Manpage.md
index 4c52da70ef..da305f8176 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -3976,6 +3976,11 @@ command execution e.g. `$(cat file)`.
   
   *Default:* `$EDITOR` or `$VISUAL`.
 
+`HOMEBREW_ENV_SYNC_STRICT`
+
+: If set, `brew *env-sync` will only sync the exact installed versions of
+  formulae.
+
 `HOMEBREW_EVAL_ALL`
 
 : If set, `brew` commands evaluate all formulae and casks, executing their
diff --git a/manpages/brew.1 b/manpages/brew.1
index 58cc2e6324..be4ea01821 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -2587,6 +2587,9 @@ Use this editor when editing a single formula, or several formulae in the same d
 \fIDefault:\fP \fB$EDITOR\fP or \fB$VISUAL\fP\&\.
 .RE
 .TP
+\fBHOMEBREW_ENV_SYNC_STRICT\fP
+If set, \fBbrew *env\-sync\fP will only sync the exact installed versions of formulae\.
+.TP
 \fBHOMEBREW_EVAL_ALL\fP
 If set, \fBbrew\fP commands evaluate all formulae and casks, executing their arbitrary code, by default without requiring \fB\-\-eval\-all\fP\&\. Required to cache formula and cask descriptions\.
 .TP