Luau getting child of variable with type


I have a problem when trying to index a child of, in my case, a model when the model has a type. I found a related post with a solution, but that only worked for plain variables, not tables with types. Here is my code:

export type WorldMarkerClass = {
    Enabled: boolean,
    Model: model,

-- later on
function WorldMarkerClass:Init()
     self.Model.SomeChildName -- does not work

Any help is appreciated.