Why doesn't dynamic partial mocking work for JMockit's @Injectable?

In the following test case where no Expectations have been recorded, I would expect that the dynamic partial mocking feature will be used for the fields A and B which are initialized in UnitToTest using @Injectable. But instead always the method calls are mocked. Only using an invalid filter value for static partial mocking, it is possible to call the real methods:

@Service
class A {
 public String doSomething() {  return "doSomething";   }
 public String doSomethingElse() {  return "doSomethingElse";   }
}

@Service
class B {
 public String doSomething() {  return "doSomething";   }
 public String doSomethingElse() {  return "doSomethingElse";   }
}

@Service
class UnitToTest {
 @Autowired B b;
 @Autowired A a;
 public B getB() {  return b;   }
 public A getA() {  return a;   }
}

public class TestClass {
 @Tested    UnitToTest unit;
 // @Mocked({ "someInvalidFilter()" })
 @Injectable    A a;
 // @Mocked({ "someInvalidFilter()" })
 @Injectable    B b;

 @Test
 public void test() {
    // actual return value is always null if no invalid static partial
    // mocking filters are specified above
    assertEquals("doSomething", unit.getA().doSomething());
    assertEquals("doSomethingElse", unit.getA().doSomethingElse());
    assertEquals("doSomething", unit.getB().doSomething());
    assertEquals("doSomethingElse", unit.getB().doSomethingElse());
 }
}

For me it looks like dynamic partial mocking with JMockit doesn't work for @Injectables. Is that a known restriction?