diff --git a/collects/typed-scheme/private/base-env.ss b/collects/typed-scheme/private/base-env.ss
index 00c6d8e7..348d36af 100644
--- a/collects/typed-scheme/private/base-env.ss
+++ b/collects/typed-scheme/private/base-env.ss
@@ -105,8 +105,8 @@
      [read (cl-> 
             [(-Port) -Sexp]
             [() -Sexp])]
-     [ormap (-polydots (a b) (->... (list (->... (list a) (b b) B) (-lst a)) ((-lst b) b) B))]
-     [andmap (-polydots (a b) (->... (list (->... (list a) (b b) B) (-lst a)) ((-lst b) b) B))]
+     [ormap (-polydots (a c b) (->... (list (->... (list a) (b b) c) (-lst a)) ((-lst b) b) c))]
+     [andmap (-polydots (a c b) (->... (list (->... (list a) (b b) c) (-lst a)) ((-lst b) b) c))]
      [newline (cl-> [() -Void]
                     [(-Port) -Void])]
      [not (-> Univ B)]
@@ -256,8 +256,8 @@
                  [(-Pathlike (-> a) Sym) a]))]
      
      [random (cl->
-              [(N) N]
-              [() N])]
+              [(-Integer) -Integer]
+              [() -Integer])]
      
      [assoc (-poly (a b) (a (-lst (-pair a b)) . -> . (-opt (-pair a b))))]
      [assf  (-poly (a b)
diff --git a/collects/typed-scheme/private/prims.ss b/collects/typed-scheme/private/prims.ss
index 2414b552..5c838d63 100644
--- a/collects/typed-scheme/private/prims.ss
+++ b/collects/typed-scheme/private/prims.ss
@@ -305,10 +305,13 @@ This file defines two sorts of primitives. All of them are provided into any mod
 (define-syntax (define-typed-struct stx)
   (syntax-case stx (:)
     [(_ nm ([fld : ty] ...) . opts)
-     (with-syntax ([d-s (syntax-property (syntax/loc stx (define-struct nm (fld ...) . opts))
-                                         'typechecker:ignore #t)]
-                   [dtsi (internal (syntax/loc stx (define-typed-struct-internal nm ([fld : ty] ...))))])
-       #'(begin d-s dtsi))]
+     (let ([mutable (if (memq '#:mutable (syntax->datum #'opts))
+                        '(#:mutable)
+                        '())])
+       (with-syntax ([d-s (syntax-property (syntax/loc stx (define-struct nm (fld ...) . opts))
+                                           'typechecker:ignore #t)]
+                     [dtsi (internal (quasisyntax/loc stx (define-typed-struct-internal nm ([fld : ty] ...) #,@mutable)))])
+         #'(begin d-s dtsi)))]
     [(_ (vars ...) nm ([fld : ty] ...) . opts)
      (with-syntax ([d-s (syntax-property (syntax/loc stx (define-struct nm (fld ...) . opts))
                                          'typechecker:ignore #t)]