diff --git a/actionview/lib/action_view/lookup_context.rb b/actionview/lib/action_view/lookup_context.rb
index 5fff6b0771..ac89fb0829 100644
--- a/actionview/lib/action_view/lookup_context.rb
+++ b/actionview/lib/action_view/lookup_context.rb
@@ -66,7 +66,7 @@ module ActionView
       def self.get(details)
         if details[:formats]
           details = details.dup
-          syms    = Set.new Mime::SET.symbols
+          syms    = Mime::SET.symbols
           details[:formats] = details[:formats].select { |v|
             syms.include? v
           }