Method Security does not switch to Interface Proxies for final Classes

If Spring Security's method security is used on a final class that implements an interface it fails. Instead it should create an interface based proxy

For example:

public interface BankAccountService {
	BankAccount findById(int id);
}

@Service
public final class BankAccountServiceImpl implements BankAccountService {
	@PostAuthorize("returnObject?.owner == authentication?.name")
	@Override
	public BankAccount findById(int id) {
		return null;
	}
}

@SpringBootApplication
@EnableMethodSecurity
public class BankAccountApplication {

	public static void main(String[] args) {
		SpringApplication.run(BankAccountApplication.class, args);
	}

}

// fails due to final class being proxied as class based proxy instead of interface based proxy
@SpringBootTest
class BankAccountServiceTest {
	@Autowired
	BankAccountService accounts;

	@Test
	void loads() {}
}