How to return user defined type from a thread spawned?

[kd]

I have the following code
    
    
    import threadpool
    
    type
      Person = object
        name: string
        age: int
    
    proc worker(): Person =
      return Person(name: "john", age: 42)
    
    proc main() =
      
      for i in 0 .. 10:
        var t = spawn worker()
        echo type(t)
      
      sync()
    
    main()
    
    
    Run

And I have compiled with
    
    
    nim c -r --threads:on test.nim
    
    
    Run

But I get Error: cannot create a flowVar of type: Person. I've tried using 
object and tuple but I still get the same error. Is there a way to do this or 
am I doing something wrong?