diff --git a/include/mapnik/attribute.hpp b/include/mapnik/attribute.hpp
index d4172ab9c..bc37461b6 100644
--- a/include/mapnik/attribute.hpp
+++ b/include/mapnik/attribute.hpp
@@ -30,8 +30,6 @@
 
 namespace mapnik {
 
-static mapnik::value _null_value;
-
 struct attribute
 {
     std::string name_;
@@ -39,16 +37,11 @@ struct attribute
         : name_(name) {}
     
     template <typename V ,typename F>
-    V value(F const& f) const
+    V const& value(F const& f) const
     {
-        typedef typename F::const_iterator const_iterator;
-        const_iterator itr = f.find(name_);
-        if (itr != f.end())
-        {
-            return itr->second;
-        }
-        return _null_value;
+        return f.get(name_); 
     }
+    
     std::string const& name() const { return name_;}
 };
 }