diff --git a/actionpack/test/template/form_helper_test.rb b/actionpack/test/template/form_helper_test.rb
index 4538b6d..b9420d0 100644
--- a/actionpack/test/template/form_helper_test.rb
+++ b/actionpack/test/template/form_helper_test.rb
@@ -447,6 +447,40 @@ class FormHelperTest < ActionView::TestCase
     assert_dom_equal expected, _erbout
   end
 
+  def test_nested_fields_for_with_nested_collections
+    _erbout = ''
+    form_for('post[]', @post) do |f|
+      _erbout.concat f.text_field(:title)
+      f.fields_for('comment[]', @comment) do |c|
+        _erbout.concat c.text_field(:name)
+      end
+    end
+
+    expected = "<form action='http://www.example.com' method='post'>" +
+               "<input name='post[123][title]' size='30' type='text' id='post_123_title' value='Hello World' />" +
+               "<input name='post[123][comment][][name]' size='30' type='text' id='post_123_comment__name' value='new comment' />" +
+               "</form>"
+
+    assert_dom_equal expected, _erbout
+  end
+  
+  def test_nested_fields_for_with_index
+    _erbout = ''
+    form_for('post', @post, :index => 1) do |c|
+      _erbout.concat c.text_field(:title)
+      c.fields_for('comment', @comment, :index => 1) do |r|
+        _erbout.concat r.text_field(:name)
+      end
+    end
+
+    expected = "<form action='http://www.example.com' method='post'>" +
+               "<input name='post[1][title]' size='30' type='text' id='post_1_title' value='Hello World' />" +
+               "<input name='post[1][comment][1][name]' size='30' type='text' id='post_1_comment_1_name' value='new comment' />" +
+               "</form>"
+
+    assert_dom_equal expected, _erbout
+  end
+
   def test_fields_for
     _erbout = ''