diff --git a/Library/Homebrew/PATH.rb b/Library/Homebrew/PATH.rb
index 4f46be178a..ac9f408a93 100644
--- a/Library/Homebrew/PATH.rb
+++ b/Library/Homebrew/PATH.rb
@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+# Represention of a `*PATH` environment variable.
+#
+# @api private
 class PATH
   include Enumerable
   extend Forwardable