diff --git a/collects/tests/typed-scheme/succeed/struct:-mutable.rkt b/collects/tests/typed-scheme/succeed/struct:-mutable.rkt
new file mode 100644
index 00000000..3ea0c171
--- /dev/null
+++ b/collects/tests/typed-scheme/succeed/struct:-mutable.rkt
@@ -0,0 +1,6 @@
+#lang typed/racket
+
+(struct: foo ([x : Integer]) #:mutable)
+
+(: f (Integer -> foo))
+(define (f x) (foo x))
\ No newline at end of file
diff --git a/collects/typed-scheme/typecheck/tc-toplevel.rkt b/collects/typed-scheme/typecheck/tc-toplevel.rkt
index 5acdfdbb..bb330b89 100644
--- a/collects/typed-scheme/typecheck/tc-toplevel.rkt
+++ b/collects/typed-scheme/typecheck/tc-toplevel.rkt
@@ -97,6 +97,11 @@
                                 (#%plain-app values)))
        (tc/struct #'nm (syntax->list #'(fld ...)) (syntax->list #'(ty ...)) 
 		  #:maker #'m)]
+      [(define-values () (begin (quote-syntax (define-typed-struct-internal nm ([fld : ty] ...)
+						#:maker m #:mutable)) 
+                                (#%plain-app values)))
+       (tc/struct #'nm (syntax->list #'(fld ...)) (syntax->list #'(ty ...)) 
+		  #:maker #'m #:mutable #t)]
       [(define-values () (begin (quote-syntax (define-typed-struct-internal (vars ...) nm ([fld : ty] ...)
 						#:maker m)) 
                                 (#%plain-app values)))
@@ -107,7 +112,10 @@
        (tc/struct #'nm (syntax->list #'(fld ...)) (syntax->list #'(ty ...)) #:type-only #t)]
       ;; define-typed-struct w/ polymorphism
       [(define-values () (begin (quote-syntax (define-typed-struct-internal (vars ...) nm ([fld : ty] ...))) (#%plain-app values)))
-       (tc/poly-struct (syntax->list #'(vars ...)) #'nm (syntax->list #'(fld ...)) (syntax->list #'(ty ...)))]    
+       (tc/poly-struct (syntax->list #'(vars ...)) #'nm (syntax->list #'(fld ...)) (syntax->list #'(ty ...)))]
+      ;; error in other cases
+      [(define-values () (begin (quote-syntax (define-typed-struct-internal . _)) (#%plain-app values)))
+       (int-err "unknown structure form")]
       
       ;; executable structs - this is a big hack
       [(define-values () (begin (quote-syntax (define-typed-struct/exec-internal nm ([fld : ty] ...) proc-ty)) (#%plain-app values)))