Estou tentando usar o suporte anotado do TX Spring.

XML do contexto do aplicativo:

<?xml ...>

    <tx:annotation-driven/>

    <bean id="dataSource" class="oracle.jdbc.pool.OracleDataSource">
        ...
    </bean>

    <bean id="repository" class="Repository">
        <constructor-arg ref="dataSource"/>
    </bean>
</beans>

Código atual:

public class Repository {
    @Transactional
        public void save(Op op) {
            System.out.println("Transaction active:::: " + TransactionSynchronizationManager.isActualTransactionActive());

    ...
    }
}

Código de chamada:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"/integration-context.xml"})
public class RepositoryTest {
    @Autowired
    private Repository repository;          

    @Test
    public void testRepositoryPersistence() {
        Op op = mock(Op.class);

        repository.save(op);
    }
}

E dáFALSO.

O que estou fazendo errado?