[plt-scheme] symbols and keywords

I am trying to get a PLT 103 program to run in PLT 200. I used to use a copied function:

(define (make-keyword symbol)
  (cond ((not (defined? symbol))
         (global-defined-value symbol symbol)
         (keyword-name symbol))
        ((not (or (eq? (global-defined-value symbol) symbol)
                  (eq? symbol ':))) ; MrSpidy compatibility has a ":" macro
         (error 'make-keyword
                "symbol ~e is already bound, can't make it a keyword." symbol))
        ((not (keyword-name? symbol)) (keyword-name symbol))
        (else #t)))


What do you do in PLT 200?

Thanks,

Alex