diff --git a/app/models/site_feed_annc.rb b/app/models/site_feed_annc.rb
index cd781b7..dd5d4a5 100644
--- a/app/models/site_feed_annc.rb
+++ b/app/models/site_feed_annc.rb
@@ -15,7 +15,7 @@ class SiteFeedAnnc
   I18n.available_locales.each do |locale|
     index({ "all_contents_for_feed.#{locale}.is_hidden"=> -1,
             "all_contents_for_feed.#{locale}.is_top"=> -1,
-            "all_contents_for_feed.#{locale}.postdate"=> -1}, { unique: false, background: true })
+            "all_contents_for_feed.#{locale}.postdate"=> -1}, { unique: false, background: true, name: "cache_#{locale}" })
   end
   def get_annc(annc_uid)
     Array(self[:all_contents_for_feed]).select{|v| v['id']==annc_uid}[0] rescue {}