diff --git a/Library/Homebrew/os/linux/glibc.rb b/Library/Homebrew/os/linux/glibc.rb
index c7073b39f3..a42ee092d0 100644
--- a/Library/Homebrew/os/linux/glibc.rb
+++ b/Library/Homebrew/os/linux/glibc.rb
@@ -2,6 +2,9 @@
 
 module OS
   module Linux
+    # Helper functions for querying `glibc` information.
+    #
+    # @api private
     module Glibc
       module_function