<!-- Thanks for submitting an issue to AssemblyScript! Please take a moment to read the contributing guidelines linked below to get off to a good start 🙂 --> Input: ```ts abstract class ASPKGElement { protected useShadow: boolean = true } class NavBar extends ASPKGElement { protected useShadow: boolean = false } ``` [TS example](https://www.typescriptlang.org/play?#code/IYIwzgLgTsDGEAJYBthjAgggZQAoGkBxAUWQFMBbMgO0TIA8IaATDACQBUBZAGVMpqIA3gCgE4hAAcoAeybwyzBAFcwZbAAtgzGQHcAXAhAyZ5YNQQBeBNGVkRAXxEiUaDADlgANwBCwKAgMTNSsWHhE-FS0CKISUrLyTEqq6lo6BkYmZhbWAGbAyGqOQA) with no error [AS example](https://www.assemblyscript.org/editor.html#IyFvcHRpbWl6ZT1zcGVlZCZydW50aW1lPXN0dWIKYWJzdHJhY3QgY2xhc3MgQVNQS0dFbGVtZW50IHsKICAgIHByb3RlY3RlZCB1c2VTaGFkb3c6IGkzMiA9IDAKfQoKY2xhc3MgTmF2QmFyIGV4dGVuZHMgQVNQS0dFbGVtZW50IHsKICAgIHByb3RlY3RlZCB1c2VTaGFkb3c6IGkzMiA9IDEKfQoKZXhwb3J0IGZ1bmN0aW9uIGZpYihuOiBpMzIpOiBpMzIgewogIGNvbnN0IHMgPSBuZXcgTmF2QmFyCiAgcmV0dXJuIHMudXNlU2hhZG93Cn0KIyFodG1sCjx0ZXh0YXJlYSBpZD0ib3V0cHV0IiBzdHlsZT0iaGVpZ2h0OiAxMDAlOyB3aWR0aDogMTAwJSIgcmVhZG9ubHk+PC90ZXh0YXJlYT4KPHNjcmlwdD4KbG9hZGVyLmluc3RhbnRpYXRlKG1vZHVsZV93YXNtLCB7IC8qIGltcG9ydHMgKi8gfSkKICAudGhlbigoeyBleHBvcnRzIH0pID0+IHsKICAgIGNvbnN0IG91dHB1dCA9IGRvY3VtZW50LmdldEVsZW1lbnRCeUlkKCdvdXRwdXQnKQogICAgZm9yIChsZXQgaSA9IDA7IGkgPD0gMTA7ICsraSkgewogICAgICBvdXRwdXQudmFsdWUgKz0gYGZpYigke2l9KSA9ICR7ZXhwb3J0cy5maWIoaSl9XG5gCiAgICB9CiAgfSkKPC9zY3JpcHQ+) with error I think this is an `enhancement` issue, right?