diff --git a/Library/Homebrew/os/mac/xcode.rb b/Library/Homebrew/os/mac/xcode.rb
index 5e9c8d6180..9aa9ba746d 100644
--- a/Library/Homebrew/os/mac/xcode.rb
+++ b/Library/Homebrew/os/mac/xcode.rb
@@ -203,6 +203,9 @@ module OS
       end
     end
 
+    # Helper module for querying macOS Command Line Tools information.
+    #
+    # @api private
     module CLT
       module_function