Autowire not working in Spring test

I created a simple RestController which autowires EntityManager and an other class I have. If I run my app, everything works, the autowires are defined. Now I tried to create a simple test for my class:

@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration
@EnableWebMvc
@ContextConfiguration(classes = MonitoringController.class)
public class MonitoringControllerTest {

    private MockMvc mockMvc;

    @Autowired
    WebApplicationContext wac;

    @Before
    public void setup() {mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();

    }

    @Test
    public void testMonitoringIsUp()throws Exception {
        mockMvc.perform(get("/monitoring"))
                .andExpect(status().isOk());
    }

Here starts the problem, I'm getting error Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'monitoringController': Unsatisfied dependency expressed through field 'em'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'javax.persistence.EntityManager' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

I guess I'm missing something very simple. Any help appreciated.