diff --git a/Library/Homebrew/cask/topological_hash.rb b/Library/Homebrew/cask/topological_hash.rb
index 919dc161f7..bfd8573827 100644
--- a/Library/Homebrew/cask/topological_hash.rb
+++ b/Library/Homebrew/cask/topological_hash.rb
@@ -2,8 +2,8 @@
 
 require "tsort"
 
-# a basic topologically sortable hashmap
 module Cask
+  # Topologically sortable hash map.
   class TopologicalHash < Hash
     include TSort