// Revision 2
em.getTransaction().begin();
entity = em.find(PropertyNotUpdatableEntity.class, entity.getId());
entity.setData("modified data");
entity.setConstantData1(null);  // @Column(updatable = false)
em.merge(entity);
em.getTransaction().commit();

// Revision 3
em.getTransaction().begin();
entity = em.find(PropertyNotUpdatableEntity.class, entity.getId()); // Use EntityManager#refresh() instead.
// Here entity.getConstantData1() returns null and it will cause Envers to operate incorrectly (put null in the audit table).
em.getTransaction().commit();