diff --git a/Library/Homebrew/dev-cmd/ruby.rb b/Library/Homebrew/dev-cmd/ruby.rb
index 5cfe6ea0d7f7a..24ca0ae004077 100644
--- a/Library/Homebrew/dev-cmd/ruby.rb
+++ b/Library/Homebrew/dev-cmd/ruby.rb
@@ -13,6 +13,8 @@ def ruby_args
         Run a Ruby instance with Homebrew's libraries loaded, e.g.
         `brew ruby -e "puts :gcc.f.deps"` or `brew ruby script.rb`.
       EOS
+      switch "-r",
+             description: "Load a library using `require`."
       switch "-e",
              description: "Execute the given text string as a script."
       switch :verbose
diff --git a/docs/Manpage.md b/docs/Manpage.md
index 76c4464ef18c3..036685a17e8dc 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -914,6 +914,8 @@ provided it defaults to `origin/master`.
 Run a Ruby instance with Homebrew's libraries loaded, e.g. `brew ruby -e "puts
 :gcc.f.deps"` or `brew ruby script.rb`.
 
+* `-r`:
+  Load a library using `require`.
 * `-e`:
   Execute the given text string as a script.
 
diff --git a/manpages/brew.1 b/manpages/brew.1
index cd254a8a38a5e..67d3d9b1b3eec 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -1157,6 +1157,10 @@ Print as a Markdown list\.
 Run a Ruby instance with Homebrew\'s libraries loaded, e\.g\. \fBbrew ruby \-e "puts :gcc\.f\.deps"\fR or \fBbrew ruby script\.rb\fR\.
 .
 .TP
+\fB\-r\fR
+Load a library using \fBrequire\fR\.
+.
+.TP
 \fB\-e\fR
 Execute the given text string as a script\.
 .