Thank you.  I agree with John that posting on the SRFI's mailing list is the right way to announce errors.  However, to make the correction easier to find, I've added a link to an Errata page to the Status section of SRFI 48.  (If the author responds with agreement and the error is straightforward like this one, I'm open to editing the document as we did with SRFI 117.  I've added a description of this errata process to the FAQ.)