diff --git a/app/models/site_feed_annc.rb b/app/models/site_feed_annc.rb
index 98dc952..e347fcb 100644
--- a/app/models/site_feed_annc.rb
+++ b/app/models/site_feed_annc.rb
@@ -177,6 +177,7 @@ class SiteFeedAnnc
               }
       }
     ]
+    max_len = 0 if (max_len.to_i < 0 rescue true)
     if max_len
       pipeline << {"$limit"=> max_len}
     end