diff --git a/Library/Homebrew/os/linux/kernel.rb b/Library/Homebrew/os/linux/kernel.rb
index 31680b9e7e..1c20ce5a14 100644
--- a/Library/Homebrew/os/linux/kernel.rb
+++ b/Library/Homebrew/os/linux/kernel.rb
@@ -2,6 +2,9 @@
 
 module OS
   module Linux
+    # Helper functions for querying Linux kernel information.
+    #
+    # @api private
     module Kernel
       module_function