Class from a different module results in java.lang.IllegalArgumentException: Not a managed type

I am trying to create a test configuration for my test slice, e.g.:

@EntityScan(basePackageClasses = {.....})
@ComponentScan(basePackageClasses = {.....})
@EnableJpaRepositories(basePackageClasses = {
        DummyClass1.class,
        DummyClass2.class,
        DummyClass3.class,
        DifferentModuleDummyClass4.class,
})
@EnableAutoConfiguration
@Configuration
public class DummyConfig {
}

And then I add it to my test:

@RunWith(SpringRunner.class)
@SpringBootTest(classes = {
        DummyConfig.class
})
public class DummyTest {
...

However I am getting the error java.lang.IllegalArgumentException: Not a managed type specifically for the class DifferentModuleDummyClass4.class that does not belong to the same module as everything else. Does anyone know what I am missing?

Thank you for your help.