Duplicate class error in android studio

I'm using android studio.
My code base is located in app/src/java, unit tests in app/src/test/java and instrumented tests in app/src/androidTest/java.
For a class named Foo I can create a unit test FooTest but as I create an instrumented test FooTest I get dublicate class error.
Is there any way I can resolve this, or I should change one of test classes?