diff --git a/lib/bldr/node.rb b/lib/bldr/node.rb
index 0bb3cf7..2ebfe0a 100644
--- a/lib/bldr/node.rb
+++ b/lib/bldr/node.rb
@@ -204,7 +204,7 @@ def attribute(*args,&block)
       if block_given?
         raise(ArgumentError, "You may only pass one argument to #attribute when using the block syntax.") if args.size > 1
         raise(ArgumentError, "You cannot use a block of arity > 0 if current_object is not present.") if block.arity > 0 and current_object.nil?
-        merge_result!(args.first, (block.arity == 1) ? block.call(current_object) : current_object.instance_eval(&block))
+        merge_result! args.first, block.call(current_object)
       else
         case args.size
         when 1 # inferred object
diff --git a/spec/fixtures/nested_objects.json.bldr b/spec/fixtures/nested_objects.json.bldr
index f2bddc9..66ff38e 100644
--- a/spec/fixtures/nested_objects.json.bldr
+++ b/spec/fixtures/nested_objects.json.bldr
@@ -1,8 +1,8 @@
 
 object :person => bert do
   attributes :name, :age
-  attribute :name_age do
-    "#{name} #{age}"
+  attribute :name_age do |person|
+    "#{person.name} #{person.age}"
   end
 
   object :friend => ernie do