1 files changed, 6 insertions, 0 deletions
diff --git a/actionpack/lib/action_view/renderer/abstract_renderer.rb b/actionpack/lib/action_view/renderer/abstract_renderer.rb
index 0b5d3785d4..b79b89e142 100644
--- a/actionpack/lib/action_view/renderer/abstract_renderer.rb
+++ b/actionpack/lib/action_view/renderer/abstract_renderer.rb
@@ -37,5 +37,11 @@ module ActionView
     def instrument(name, options={})
       ActiveSupport::Notifications.instrument("render_#{name}.action_view", options){ yield }
     end
+
+    def prepend_formats(formats)
+      formats = Array(formats)
+      return if formats.empty? || @lookup_context.html_fallback_for_js
+      @lookup_context.formats = formats | @lookup_context.formats
+    end
   end
 end