lateinit property mock object has not been initialized

I'm trying to initialize (by mocking) two objects with the annotation @MockBean

It seems only to work if i call the method mock(className), but since i want to use the mocked class on multiple methods i don't want to keep repeating the same code in my test methods.

This is my test class:

@RunWith(MockitoJUnitRunner::class)
class WordServiceTest {

    @MockBean
    lateinit var wordRepositoryMock: WordRepository

    @MockBean
    private lateinit var wordMapperMock: WordMapper

    @Test
    fun findAllTest() {
        // Error: lateinit property wordRepositoryMock has not been initialized
        val wordService = WordService(wordRepositoryMock, wordMapperMock)
        `when`(wordRepositoryMock.findAll()).thenReturn(listOf(
                WordEntity(UUID.randomUUID(), "xxx"),
                WordEntity(UUID.randomUUID(), "xxx")))
        assertEquals(2, wordService.findAll().size)
    }

    @Test
    fun wordExistsTest() {
        // This works fine
        val wordRepositoryMock = mock(WordRepository::class.java)
        val wordMapperMock = mock(WordMapper::class.java)
        val wordService = WordService(wordRepositoryMock, wordMapperMock)
        val word = "xxx"
        `when`(wordRepositoryMock.existsWordEntityByName(word)).thenReturn(true)
        assertEquals(true, wordService.wordExists(word))
    }
}

I don't want to use the Spring Boot @Autowired annotation because my spring application requires contexts which i don't want to load.

The error i'm getting:

lateinit property wordRepositoryMock has not been initialized
kotlin.UninitializedPropertyAccessException: lateinit property wordRepositoryMock has not been initialized