diff --git a/Library/Homebrew/cask/audit.rb b/Library/Homebrew/cask/audit.rb
index f5cd9c231..70f5d364c 100644
--- a/Library/Homebrew/cask/audit.rb
+++ b/Library/Homebrew/cask/audit.rb
@@ -8,6 +8,9 @@ require "utils/git"
 require "utils/notability"
 
 module Cask
+  # Audit a cask for various problems.
+  #
+  # @api private
   class Audit
     extend Predicable