diff --git a/Library/Homebrew/requirements/linux_requirement.rb b/Library/Homebrew/requirements/linux_requirement.rb
index 74daf4cf4a..04b644a398 100644
--- a/Library/Homebrew/requirements/linux_requirement.rb
+++ b/Library/Homebrew/requirements/linux_requirement.rb
@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+# A requirement on Linux.
+#
+# @api private
 class LinuxRequirement < Requirement
   fatal true