Argument type Element is not assignable to parameter type HTMLxxxElement

Firstly, this is very similar to the following:

https://intellij-support.jetbrains.com/hc/en-us/community/posts/206364059-Argument-type-is-not-assignable-to-parameter-type-when-passing-child

Basically, I'm assigning a variable as follows:

var basis_control = document.getElementById('flex-basis-field');

and then passing basis_control to another function whose parameter in JSdoc is declared as {HTMLSelectElement}.

I could go on ignoring statements, but perhaps I'm commenting wrong.

How do I tell the system that document.getElementById is in fact returning a HTMLSelectElement?

Thanks,

Gary