diff --git a/lib/multi_xml.rb b/lib/multi_xml.rb
index f3873f7..26ac6ea 100644
--- a/lib/multi_xml.rb
+++ b/lib/multi_xml.rb
@@ -10,7 +10,7 @@ class NoParserError < StandardError; end
 
   class DisallowedTypeError < StandardError
     def initialize(type)
-      super "Disallowed type attribute: #{type.inspect}"
+      super("Disallowed type attribute: #{type.inspect}")
     end
   end