diff --git a/docs/Manpage.md b/docs/Manpage.md
index 2aa5bc9ed3..0b7aca2828 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -1394,6 +1394,9 @@ Note that environment variables must have a value set to be detected. For exampl
 
     *Default:* `15`.
 
+  * `HOMEBREW_FORBIDDEN_LICENSES`:
+    Use this environment variable to define a blacklist of space separated licenses and Homebrew will avoid installing the packages with those licenses.
+
   * `HOMEBREW_FORCE_BREWED_CURL`:
     If set, always use a Homebrew-installed `curl`(1) rather than the system version. Automatically set if the system version of `curl` is too old.