Android : Extending a class in a different module, builds in Android Studio but cannot resolve symbols

In my project, I have module A with com.example.foo which I want to extend a class in that module in my module B which is com.example.foo.bar. I've added module A as a dependency in module B and it builds just fine.

My problem starts when I'm trying to extend the class as so:

package com.example.foo.bar;

public class Subject extends com.example.foo.SomeClass {
    ...
}

In Android Studio, all the references to module A show up as red (since it cannot resolve those symbols), but I can still successfully build my project regardless.

How do I configure AS to properly recognize the dependency?