diff --git a/lib/haml/buffer.rb b/lib/haml/buffer.rb
index <HASH>..<HASH> 100644
--- a/lib/haml/buffer.rb
+++ b/lib/haml/buffer.rb
@@ -277,7 +277,7 @@ RUBY
       ref_id =
         if ref.respond_to?(:to_key)
           key = ref.to_key
-          key.join('_') unless key.nil? #TODO further sanitize each key like dom_id
+          key.join('_') unless key.nil?
         else
           ref.id
         end
Get rid of a TODO.