Serializing of dbms_scheduler event based jobs

The default behaviour of DBMS_SCHEDULER event-based jobs is to ignore the event if the job is running at the time of a new event. There is possibility to run the jobs in parallel using the job attribute PARALLEL_INSTANCES set to TRUE.
The question is how to obtain serialized event based jobs - i.e. the event is not ignored if the job is running, but the start of the job is delayed until the previous job is finished.
Of course the job itself can do some locking to enforce the serialization - but is there some more simple and native way?

Kind regards,

Jaromir D.B. Nemec

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