Autowiring in custom jsr validator

So I followed the documentation on this page to make dependency injection in custom jsr validators work. As I understand it I need to add a LocalValidatorFactoryBean to my config, which I did here:

    @Configuration
public class ValidatorConfig {

    //Used to make sure custom validators get picked up
    @Bean
    public LocalValidatorFactoryBean validator(){
        return new LocalValidatorFactoryBean();
    }
}

This works in all my test-suites except for one:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader = AnnotationConfigContextLoader.class, classes = JpaConfig.class)
@ActiveProfiles(Profiles.TEST)
public class UserLifeCycleTestCase {

    @Autowired
    private UserJpaRepository userJpaRepository;

    @Autowired
    private CountryJpaRepository countryJpaRepository;

    @Test
    public void ageShouldBeCorrectBecauseEntityIsPeristed(){
        User user = new User("robin.hellemans@realdolmen.com", "Robin0", "Robin", "Hellemans", new Date(), "Molenstraat", 82, "Londerzeel", "1840", countryJpaRepository.findOne(1L));
        userJpaRepository.saveAndFlush(user);
        assertNotNull(user.getPerson().getAge());
    }
}

Relevant part of JpaConfig.class:

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "com.robin.repository")
@EnableJpaAuditing
//Picks up other @Configuration classes as well
@ComponentScan(basePackages = "com.robin")
public class JpaConfig {

In this testcase the JpaRepository (which is a Spring Data Jpa repository) is null. The validator: (I doubt there's anything wrong with it since other test cases also depend on this one and run successfully)

public class UniqueUserNameValidator implements ConstraintValidator<UniqueUserName, String>{

    @Autowired
    private UserJpaRepository userJpaRepository;

    @Override
    public void initialize(UniqueUserName constraintAnnotation) {

    }
@Override
public boolean isValid(String value, ConstraintValidatorContext context) {
    return userJpaRepository.findByUserName(value) == null;
}

}

In my other test suits this is not the case, an example in which my repo's do get autowired:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader = AnnotationConfigContextLoader.class, classes = JpaConfig.class)
@ActiveProfiles(Profiles.TEST)
public class CountryValidationTestCase {

    @Autowired
    private Validator validator;

      //Tests

Looking at the documentation, I did nothing wrong, so I really can't see the problem here.