diff --git a/lib/html2markdown/converter.rb b/lib/html2markdown/converter.rb
index 2bb23c9..bda65a1 100644
--- a/lib/html2markdown/converter.rb
+++ b/lib/html2markdown/converter.rb
@@ -27,7 +27,7 @@ def parse_element(ele)
 
     # wrap node with markdown
     def wrap_node(node,contents=nil)
-      result = ''
+      result = String.new
       contents.strip! unless contents==nil
       # check if there is a custom parse exist
       if respond_to? "parse_#{node.name}"