[racket] Declaring type of identifier defined which typed/racket exports as untyped.

This program:

#lang typed/racket
integer-sqrt/remainder

Gives the error:
Type Checker: untyped identifier integer-sqrt/remainder imported from
module <typed/racket> in: integer-sqrt/remainder


And this program:

#lang typed/racket
(: integer-sqrt/remainder : Natural Natural -> Natural)

 gives this error:

Type Checker: Declaration for integer-sqrt/remainder provided, but
integer-sqrt/remainder is defined in another module in:
integer-sqrt/remainder

How do I fix this?


/Jens Axel