Hi Robert, Thanks for the quick reply (and all your hard work on the library...). I understand what you are saying, that makes a lot of sense. I don't see any other way to ensure the integrity of the shared_ptr than to forbid track_never. However, it still seems strange that when I serialize the shared_ptr the second time (after the pointed-to object has been changed), what is serialized does not reflect any change. It's almost like it would be safer to forbid serialization of shared_ptr to non-const objects, altogether... Anyway, thank you for the explanation, it is much appreciated. Frank -- View this message in context: http://boost.2283326.n4.nabble.com/How-to-prevent-boost-serialize-from-objec... Sent from the Boost - Users mailing list archive at Nabble.com.