not null constraints in Oracle does not keep their names in changelog

When generating a changelog file from a database in Oracle which has user given names for all constraints it seems that the not null constraints are missing their given names. Instead they are created as non-named constraints and Oracle then gives them the standard name “SYS_Cnnnnnnnn”. Is there some way to fix this or am i missing something?

It’s probably a limitation of the diff tool.  I created to track it.