diff --git a/lib/nested_form/builder_mixin.rb b/lib/nested_form/builder_mixin.rb
index 26a98877..5f31b0be 100644
--- a/lib/nested_form/builder_mixin.rb
+++ b/lib/nested_form/builder_mixin.rb
@@ -104,7 +104,9 @@ def fields_for_nested_model(name, object, options, block)
     private
 
     def fields_blueprint_id_for(association)
-      assocs = object_name.to_s.scan(/(\w+)_attributes/).map(&:first)
+      assocs = []
+      assocs << [object_name.to_s.split("[")[0]] # root
+      assocs.concat(object_name.to_s.scan(/(\w+)_attributes/).map(&:first)) # parent associations
       assocs << association
       assocs.join('_') + '_fields_blueprint'
     end
diff --git a/spec/nested_form/builder_spec.rb b/spec/nested_form/builder_spec.rb
index 98456b72..6455b986 100644
--- a/spec/nested_form/builder_spec.rb
+++ b/spec/nested_form/builder_spec.rb
@@ -19,9 +19,9 @@
 
       describe '#link_to_add' do
         it "behaves similar to a Rails link_to" do
-          subject.link_to_add("Add", :tasks).should == '<a href="javascript:void(0)" class="add_nested_fields" data-association="tasks" data-blueprint-id="tasks_fields_blueprint">Add</a>'
-          subject.link_to_add("Add", :tasks, :class => "foo", :href => "url").should == '<a href="url" class="foo add_nested_fields" data-association="tasks" data-blueprint-id="tasks_fields_blueprint">Add</a>'
-          subject.link_to_add(:tasks) { "Add" }.should == '<a href="javascript:void(0)" class="add_nested_fields" data-association="tasks" data-blueprint-id="tasks_fields_blueprint">Add</a>'
+          subject.link_to_add("Add", :tasks).should == '<a href="javascript:void(0)" class="add_nested_fields" data-association="tasks" data-blueprint-id="item_tasks_fields_blueprint">Add</a>'
+          subject.link_to_add("Add", :tasks, :class => "foo", :href => "url").should == '<a href="url" class="foo add_nested_fields" data-association="tasks" data-blueprint-id="item_tasks_fields_blueprint">Add</a>'
+          subject.link_to_add(:tasks) { "Add" }.should == '<a href="javascript:void(0)" class="add_nested_fields" data-association="tasks" data-blueprint-id="item_tasks_fields_blueprint">Add</a>'
         end
 
         it 'raises ArgumentError when missing association is provided' do
@@ -115,7 +115,7 @@
         output.should match(/div.+data-blueprint="#{expected}"/)
       end
 
-      it "adds parent association name to the blueprint div id" do
+      it "adds parent associations to the blueprint div id" do
         task = project.tasks.build
         task.milestones.build
         subject.fields_for(:tasks, :builder => builder) do |tf|
@@ -123,7 +123,7 @@
           tf.link_to_add('Add', :milestones)
         end
         output = template.send(:after_nested_form_callbacks)
-        output.should match(/div.+id="tasks_milestones_fields_blueprint"/)
+        output.should match(/div.+id="item_tasks_milestones_fields_blueprint"/)
       end
 
       it "doesn't render wrapper div" do