How to inject into Gradle Unit Test Scope (Android, Dagger)

I am using the new unit testing feature in the Gradle 1.1 Android plugin. Let's say I have a JUnit Test like this:

public class GlossaryItemJsonTest {
    @Inject
    Gson gson; //this is not getting injected, so it's null


    @Test
    public void testDeserialization() throws Exception {
        //...
    }
}

How can I inject from my main scope into my test scope? I do not want to duplicate any code from my main DataModule. Traditionally I would add an injects=GsonTest.class field to the @Module annotation, but the main DataModule cannot see any classes from the test scope.

@Module(
        injects  = GsonTest.class //does not compile
        complete = false,
        library  = true
)
public class DataModule {
    @Provides @Singleton provideGson(){...}
}

How do inject my gson variable in the Gradle test scope?