diff --git a/app/models/item/search/query.rb b/app/models/item/search/query.rb
index 0c529ae2..4ac67c7b 100644
--- a/app/models/item/search/query.rb
+++ b/app/models/item/search/query.rb
@@ -44,7 +44,7 @@ class Item
               filters << NPFilter.new(is_positive)
             else
               message = I18n.translate('items.search.errors.not_found.label',
-                :label => value)
+                :label => "is:#{value}")
               raise Item::Search::Error, message
             end
           else