[plt-scheme] enclosing-module-name

I'm not getting a value for enclosing-module-name in the following code:

(module test mzscheme
  (provide (all-defined))
  (define-syntax (test-module-name stx)
      (syntax-case stx ()
        ((_)
         (let ((prop (syntax-property stx 'enclosing-module-name)))
           #`(printf "~a\n" #,prop))))))

(require test)
(test-module-name)      ; => #f

I expected the output to be 'test'.  Any suggestions?

Wayne