diff --git a/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-app/tc-app-objects.rkt b/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-app/tc-app-objects.rkt
index 0859164f08..a608052229 100644
--- a/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-app/tc-app-objects.rkt
+++ b/pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/tc-app/tc-app-objects.rkt
@@ -60,8 +60,10 @@
     [(and c (Class: _ inits fields _ _ init-rest))
      (cond [;; too many positional arguments, fail
             (and (> (length pos-args) (length inits)) (not init-rest))
-            ;; FIXME: better message
-            (tc-error "too many positional arguments supplied")]
+            (tc-error/fields "failure in class instantiation"
+                             #:more "too many positional arguments supplied"
+                             "expected" (format "~a arguments" (length inits))
+                             "given" (format "~a arguments" (length pos-args)))]
            [;; more args than inits, now feed them to init-rest
             (and (> (length pos-args) (length inits)))
             (define-values (pos-for-inits other-pos)
@@ -80,8 +82,12 @@
               (tc-expr/check pos-arg (ret type)))
             (check-named-inits other-inits given-names name-assoc)])
      (ret (make-Instance c))]
+    [(ClassTop:) (tc-error/expr/fields "failure in class instantiation"
+                                       #:more "cannot instantiate a value of type ClassTop")]
     [t
-     (tc-error/expr "expected a class value for object creation, got: ~a" t)]))
+     (tc-error/expr/fields "failure in class instantiation"
+                           #:more "given a value of a non-class type"
+                           "given" t)]))
 
 (define (check-named-inits inits names name-assoc)
   (define init-names (map car inits))
diff --git a/pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/class-tests.rkt b/pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/class-tests.rkt
index 4eb8c5eaa9..6144489351 100644
--- a/pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/class-tests.rkt
+++ b/pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/class-tests.rkt
@@ -1420,4 +1420,11 @@
             (define/public (m arg ...) . body))
           (my-meth (hello) (displayln "hello world"))))
       (send (new c%) hello))
-    -Void]))
+    -Void]
+   ;; the next few tests check failing class instantiation
+   [tc-err (make-object object% 1)
+           #:msg #rx"expected: 0 arguments.*given: 1 arguments"]
+   [tc-err (make-object (ann object% ClassTop))
+           #:msg #rx"cannot instantiate.*ClassTop"]
+   [tc-err (make-object 3)
+           #:msg #rx"value of a non-class type"]))