diff --git a/typed-racket-test/succeed/cast-mod.rkt b/typed-racket-test/succeed/cast-mod.rkt
index 803ac2f5..a3f8d173 100644
--- a/typed-racket-test/succeed/cast-mod.rkt
+++ b/typed-racket-test/succeed/cast-mod.rkt
@@ -44,31 +44,49 @@
   (: b1 : (Boxof Integer))
   (define b1 (box 42))
   (define b2 (cast b1 (Boxof String)))
+  (define b3 (ann b1 BoxTop))
+  (define b4 (cast b3 (Boxof (U Integer String))))
   (check-equal? (unbox b1) 42)
+  (check-equal? (unbox b4) 42)
   (check-exn #rx"expected: Integer\n *given: \"hi\""
              (λ () (set-box! b2 "hi")))
   (check-equal? (unbox b1) 42
-                "if the previous test hadn't errored, this would be \"hi\" with type Integer"))
+                "if the previous test hadn't errored, this would be \"hi\" with type Integer")
+  (check-exn #rx"Attempted to use a higher-order value passed as `Any`"
+             (λ () (set-box! b4 "hello")))
+  (check-equal? (unbox b1) 42))
 
 (test-case "cast on mutable vectors"
   (: v1 : (Vectorof Integer))
   (define v1 (vector 42))
   (define v2 (cast v1 (Vectorof String)))
+  (define v3 (ann v1 VectorTop))
+  (define v4 (cast v3 (Vectorof (U Integer String))))
   (check-equal? (vector-ref v1 0) 42)
+  (check-equal? (vector-ref v4 0) 42)
   (check-exn #rx"expected: Integer\n *given: \"hi\""
              (λ () (vector-set! v2 0 "hi")))
   (check-equal? (vector-ref v1 0) 42
-                "if the previous test hadn't errored, this would be \"hi\" with type Integer"))
+                "if the previous test hadn't errored, this would be \"hi\" with type Integer")
+  (check-exn #rx"Attempted to use a higher-order value passed as `Any`"
+             (λ () (vector-set! v4 0 "hello")))
+  (check-equal? (vector-ref v1 0) 42))
 
 ;; Struct definitions need to be at the module level for some reason.
-(struct (X) s ([i : X]) #:mutable)
+(struct (X) s ([i : X]) #:mutable #:transparent)
 (test-case "cast on mutable structs"
   (: s1 : (s Integer))
   (define s1 (s 42))
   (define s2 (cast s1 (s String)))
+  (define s3 (ann s1 Any))
+  (define s4 (cast s3 (s (U Integer String))))
   (check-equal? (s-i s1) 42)
+  (check-equal? (s-i s4) 42)
   (check-exn #rx"expected: Integer\n *given: \"hi\""
              (λ () (set-s-i! s2 "hi")))
   (check-equal? (s-i s1) 42
-                "if the previous test hadn't errored, this would be \"hi\" with type Integer"))
+                "if the previous test hadn't errored, this would be \"hi\" with type Integer")
+  (check-exn #rx"Attempted to use a higher-order value passed as `Any`"
+             (λ () (set-s-i! s4 "hello")))
+  (check-equal? (s-i s1) 42))