--- PLT Scheme v4.1.3/collects/mzlib/foreign.ss~	2008-12-19 23:06:16.000000000 +0100
+++ PLT Scheme v4.1.3/collects/mzlib/foreign.ss	2008-12-19 23:06:16.000000000 +0100
@@ -1477,7 +1477,7 @@
           (identifiers? #'(slot ...)))
      (make-syntax #'_TYPE #f #'(slot ...) #'(slot-type ...))]
     [(_ (_TYPE _SUPER) ([slot slot-type] ...))
-     (and (_-identifier? #'_TYPE) (identifiers? #'(slot ...)))
+     (and (_-identifier? #'_TYPE stx) (identifiers? #'(slot ...)))
      (with-syntax ([super (datum->syntax #'_TYPE 'super #'_TYPE)])
        (make-syntax #'_TYPE #t #'(super slot ...) #'(_SUPER slot-type ...)))]))