diff --git a/lib/renderers/simple_tag.rb b/lib/renderers/simple_tag.rb
index a5de510..106f185 100644
--- a/lib/renderers/simple_tag.rb
+++ b/lib/renderers/simple_tag.rb
@@ -32,13 +32,13 @@ def c(*args)
     
     def rendered_attributes
       str = ""
-      str << " class=\"#{css_class.join(' ')}\"" unless css_class.empty?
+      str << " class=\"" << css_class.join(' ') << "\"" unless css_class.empty?
       keys = attributes.keys.sort{|a, b| a.to_s <=> b.to_s}
       keys.each do |key|
         value = attributes[key]
         if value
           value = value.to_s.gsub('"', '\'')
-          str << " #{key}=\"#{value}\""
+          str << " " << key.to_s << "=\"" << value.to_s << "\""
         end
       end
       str