How to inject mapper (mapstruct) to Junit test with SpringJUnit4ClassRunner

I have problems with configurate tests for SpringJUnit4ClassRunner.class). My problem is because my mapper from mapstruct returns null when reached.

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
class UserServiceTestSuite {
    @Spy
    private UserDto userDto;
    @Spy
    private UserMapper userMapper;
    @Mock
    private UserRepository userRepository;
    @InjectMocks
    private UserService userService;

    private User createUser() {
        return User.builder()
                .firstName("Steve")
                .lastName("Jobs")
                .login("SteveJobs")
                .password("password")
                .role(UserRole.ROLE_ADMIN)
                .build();

    }

    @Test
    public void testCreateUser() {
        //Given
        User user = createUser();
        Mockito.when(userRepository.save(user)).thenReturn(user);
        //When
        UserDto userDto = userService.createUser(userMapper.mapToUserDto(user));
        Long id = userDto.getId();
        //Then
        Assert.assertEquals("Steve", userDto.getFirstName());
        Assert.assertEquals("Jobs", userDto.getLastName());
        Assert.assertEquals("SteveJobs", userDto.getLogin());
        Assert.assertEquals("ROLE_ADMIN", userDto.getRole());
    }

Thank you for all solutions :)