diff --git a/collects/racket/contract/private/box.rkt b/collects/racket/contract/private/box.rkt
index e0731d763e..2712d39afd 100644
--- a/collects/racket/contract/private/box.rkt
+++ b/collects/racket/contract/private/box.rkt
@@ -122,7 +122,10 @@
                         (list* (cadr args) (car args) new-args)))]
              [else (append (reverse new-args)
                            (cons (syntax-property
-                                  (car args)
+                                  (syntax-property
+                                   (car args)
+                                   'racket/contract:negative-position
+                                   this-one)
                                   'racket/contract:positive-position
                                   this-one)
                                  (cdr args)))])))
diff --git a/collects/racket/contract/private/vector.rkt b/collects/racket/contract/private/vector.rkt
index 83568fb9d5..649461b7a9 100644
--- a/collects/racket/contract/private/vector.rkt
+++ b/collects/racket/contract/private/vector.rkt
@@ -25,8 +25,11 @@
       [else
        (loop (cdr args)
              (cons (syntax-property
-                    (car args)
-                    'racket/contract:positive-position
+                    (syntax-property
+                     (car args)
+                     'racket/contract:positive-position
+                     this-one)
+                    'racket/contract:negative-position
                     this-one)
                    new-args))])))