diff --git a/actionpack/lib/action_view/helpers/date_helper.rb b/actionpack/lib/action_view/helpers/date_helper.rb
index 2bfc6371f5..45e5a862b6 100644
--- a/actionpack/lib/action_view/helpers/date_helper.rb
+++ b/actionpack/lib/action_view/helpers/date_helper.rb
@@ -977,7 +977,10 @@ module ActionView
         # Returns the id attribute for the input tag.
         #  => "post_written_on_1i"
         def input_id_from_type(type)
-          input_name_from_type(type).gsub(/([\[\(])|(\]\[)/, '_').gsub(/[\]\)]/, '')
+          id = input_name_from_type(type).gsub(/([\[\(])|(\]\[)/, '_').gsub(/[\]\)]/, '')
+          id = @options[:namespace] + '_' + id if @options[:namespace]
+
+          id
         end
 
         # Given an ordering of datetime components, create the selection HTML
diff --git a/actionpack/test/template/form_helper_test.rb b/actionpack/test/template/form_helper_test.rb
index 2bdb54bd5e..c5de736ffb 100644
--- a/actionpack/test/template/form_helper_test.rb
+++ b/actionpack/test/template/form_helper_test.rb
@@ -1063,6 +1063,14 @@ class FormHelperTest < ActionView::TestCase
     assert_dom_equal expected, output_buffer
   end
 
+  def test_form_for_with_namespace_with_date_select
+    form_for(@post, :namespace => 'namespace') do |f|
+      concat f.date_select(:written_on)
+    end
+
+    assert_select 'select#namespace_post_written_on_1i'
+  end
+
   def test_form_for_with_namespace_with_label
     form_for(@post, :namespace => 'namespace') do |f|
       concat f.label(:title)