diff --git a/libraries/db/include/graphene/db/undo_database.hpp b/libraries/db/include/graphene/db/undo_database.hpp
index 4b727372..25040087 100644
--- a/libraries/db/include/graphene/db/undo_database.hpp
+++ b/libraries/db/include/graphene/db/undo_database.hpp
@@ -29,15 +29,15 @@
 namespace graphene { namespace db {
 
    using std::unordered_map;
-   using fc::flat_set;
+   using fc::flat_set;  
    class object_database;
 
    struct undo_state
    {
-      unordered_map<object_id_type, unique_ptr<object> > old_values;
-      unordered_map<object_id_type, object_id_type>      old_index_next_ids;
-      std::unordered_set<object_id_type>                 new_ids;
-      unordered_map<object_id_type, unique_ptr<object> > removed;
+      unordered_map<object_id_type, unique_ptr<object> >       old_values;
+      unordered_map<object_id_type, object_id_type>            old_index_next_ids;
+      std::set<object_id_type, std::greater<object_id_type> >  new_ids;
+      unordered_map<object_id_type, unique_ptr<object> >       removed;
    };