diff --git a/actionpack/lib/action_view/helpers/prototype_helper.rb b/actionpack/lib/action_view/helpers/prototype_helper.rb
index 40bb18c624..1dee0f69f0 100644
--- a/actionpack/lib/action_view/helpers/prototype_helper.rb
+++ b/actionpack/lib/action_view/helpers/prototype_helper.rb
@@ -425,7 +425,7 @@ module ActionView
         #
         #   # Controller action
         #   def poll
-        #     render :update { |page| page.update_time }
+        #     render(:update) { |page| page.update_time }
         #   end
         #
         # You can also use PrototypeHelper#update_page_tag instead of