diff --git a/Library/Homebrew/rubocops/files.rb b/Library/Homebrew/rubocops/files.rb
index 843972daca..d4454ad4cb 100644
--- a/Library/Homebrew/rubocops/files.rb
+++ b/Library/Homebrew/rubocops/files.rb
@@ -5,6 +5,9 @@ require "rubocops/extend/formula"
 module RuboCop
   module Cop
     module FormulaAudit
+      # This cop makes sure that a formula's file permissions are correct.
+      #
+      # @api private
       class Files < FormulaCop
         def audit_formula(node, _class_node, _parent_class_node, _body_node)
           return unless file_path