diff --git a/app/models/metadata_template.rb b/app/models/metadata_template.rb
index 5de54be1..b324e71c 100644
--- a/app/models/metadata_template.rb
+++ b/app/models/metadata_template.rb
@@ -202,7 +202,7 @@ MetadataTemplate = Struct.new(:site, :document, :name, :label, :type,
 
   def allowed_attributes
     @allowed_attributes ||= %w[style href src alt controls data-align data-multimedia data-multimedia-inner id
-                               name].freeze
+                               name start].freeze
   end
 
   def allowed_tags