diff --git a/lib/event_news_mod/migrate.rb b/lib/event_news_mod/migrate.rb
index 7488f3a..d2f3a17 100644
--- a/lib/event_news_mod/migrate.rb
+++ b/lib/event_news_mod/migrate.rb
@@ -26,6 +26,10 @@ module EventNewsMod
         setting.save
       end
 
+      #solve bug for thousands of generated feed cache
+      if EventNewsFeedCache.count > EventNewsFeed.count*5
+        EventNewsFeedCache.collection.drop
+      end
       EventNewsFeedCache.regenerate_all
 
       puts ['event news migrate end']