[racket] typed racket: inconsistent interaction between typed and untyped code?

I'm hitting an error when trying to pass values between typed and
untyped code.  I've shrunk the error to the following test code.
Consider three files 'sim-structs', 'sim.rkt', and 'test-sim.rkt'.
sim-structs and sim are written in Typed Racket, and test-sim is
written in regular racket.

;; sim-structs.rkt
#lang typed/racket/base
(provide (all-defined-out))
(define-struct: machine ([env : (Listof Any)]))  #:transparent)
(define-struct: toplevel ([vals : (Vectorof Any)])  #:transparent)


;; sim.rkt
#lang typed/racket/base
(require "sim-structs.rkt")
(provide new-machine)
(: new-machine ( -> machine))
(define (new-machine)
  (make-machine (list (make-toplevel (vector 'foobar)))))


;; test-sim.rkt
#lang racket
(require "sim.rkt" "sim-structs.rkt")
(toplevel-vals (first (machine-env (new-machine))))



When I try to execute test-sim, it fails with the following error:


tesla ~/work/js-sicp-5-5 $ /pro/plt/software/racket/5.1/std/bin/racket
test-sim.rkt
contract violation: expected <toplevel?>, given: #<Typed Value:
#(struct:toplevel #(foobar))>
  contract on toplevel-vals24 from
    (file
     /home/dyoo/work/js-sicp-5-5/sim-structs.rkt)
 via
    (file
     /home/dyoo/work/js-sicp-5-5/test-sim.rkt)
  blaming
    (file /home/dyoo/work/js-sicp-5-5/sim.rkt)
  contract: (-> toplevel? (vectorof Any))
        at: /home/dyoo/work/js-sicp-5-5/sim-structs.rkt:11.16

 === context ===
/pro/plt/software/racket/5.1/std/collects/racket/contract/private/blame.rkt:58:0:
raise-blame-error
/home/dyoo/work/js-sicp-5-5/test-sim.rkt: [running body]



It looks as though there's some special "Typed Value" wrapper there
that shouldn't be visible from the untyped test-sim code.  Is there a
workaround?