diff --git a/actionpack/lib/action_view/helpers/ajax_helper.rb b/actionpack/lib/action_view/helpers/ajax_helper.rb
index b94eb6c973..8707378738 100644
--- a/actionpack/lib/action_view/helpers/ajax_helper.rb
+++ b/actionpack/lib/action_view/helpers/ajax_helper.rb
@@ -102,7 +102,7 @@ module ActionView
         options[:name] = name
 
         <<-SCRIPT
-        <script type="application/json" data-js-type="observe_field">
+        <script type="application/json" data-js-type="field_observer">
         //<![CDATA[
           #{options.to_json}
         // ]]>
diff --git a/actionpack/test/javascript/ajax_test.rb b/actionpack/test/javascript/ajax_test.rb
index 90aa2821ec..41bfdbd9b9 100644
--- a/actionpack/test/javascript/ajax_test.rb
+++ b/actionpack/test/javascript/ajax_test.rb
@@ -354,7 +354,7 @@ class ObserveFieldTest < AjaxTestCase
 
   test "basic" do
     assert_html field,
-      %w(script type="application/json" data-js-type="observe_field")
+      %w(script type="application/json" data-js-type="field_observer")
   end
 
   test "using a url string" do