diff --git a/lib/redmine/mime_type.rb b/lib/redmine/mime_type.rb
index 202c01e41..2bd396871 100644
--- a/lib/redmine/mime_type.rb
+++ b/lib/redmine/mime_type.rb
@@ -60,7 +60,7 @@ module Redmine
         extension = m[2].downcase
         @known_types ||= Hash.new do |h, ext|
           type = EXTENSIONS[ext]
-          type ||= MIME::Types.find {|type| type.extensions.include?(ext)}.to_s.presence
+          type ||= MIME::Types.type_for(ext).first.to_s.presence
           h[ext] = type
         end
         @known_types[extension]