diff --git a/Library/Homebrew/dependable.rb b/Library/Homebrew/dependable.rb
index 2b97e7db75..89dfe083c2 100644
--- a/Library/Homebrew/dependable.rb
+++ b/Library/Homebrew/dependable.rb
@@ -2,6 +2,9 @@
 
 require "options"
 
+# Shared functions for classes which can be depended upon.
+#
+# @api private
 module Dependable
   # `:run` and `:linked` are no longer used but keep them here to avoid them being
   # misused in future.