Johannes Zick, thanks for your help. Best chances to get this fixed quickly is to provide a test case. Could could try to checkout the Hibernate Validator sources directly and create a test there. See also http://hibernate.org/validator/contribute/

You could maybe add a new test to OptionalValueUnwrapperTest. There are multiple benefits here, first you would provide a test case which can be directly used by us, meaning it will take less time to implement a fix and secondly by using the Validator test harness you can focus on just finding the minimal setup to re-produce the problem, instead of trying to abstract something from your project.