diff --git a/app/models/metadata_template.rb b/app/models/metadata_template.rb
index 5baa7a4a..d96b4b04 100644
--- a/app/models/metadata_template.rb
+++ b/app/models/metadata_template.rb
@@ -195,7 +195,7 @@ 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 rel target referrerpolicy].freeze
   end
 
   def allowed_tags