diff --git a/collects/tests/typed-scheme/optimizer/generic/box.rkt b/collects/tests/typed-scheme/optimizer/generic/box.rkt
new file mode 100644
index 00000000..aa6695de
--- /dev/null
+++ b/collects/tests/typed-scheme/optimizer/generic/box.rkt
@@ -0,0 +1,9 @@
+#lang typed/scheme #:optimize
+
+(require racket/unsafe/ops)
+
+(: x (Boxof Integer))
+(define x (box 1))
+(unbox x)
+(set-box! x 2)
+(unbox x)
diff --git a/collects/typed-scheme/optimizer/box.rkt b/collects/typed-scheme/optimizer/box.rkt
new file mode 100644
index 00000000..99efba91
--- /dev/null
+++ b/collects/typed-scheme/optimizer/box.rkt
@@ -0,0 +1,29 @@
+#lang scheme/base
+
+(require syntax/parse
+         unstable/match scheme/match
+         "../utils/utils.rkt"
+         (for-template scheme/base scheme/fixnum scheme/unsafe/ops)
+         (rep type-rep)
+         (types abbrev type-table utils subtype)
+         (optimizer utils))
+
+(provide box-opt-expr)
+
+(define-syntax-class box-expr
+  (pattern e:expr
+           #:when (match (type-of #'e)
+                    [(tc-result1: (Box: _)) #t]
+                    [_ #f])
+           #:with opt ((optimize) #'e)))
+
+(define-syntax-class box-op
+  ;; we need the * versions of these unsafe operations to be chaperone-safe
+  (pattern (~literal unbox)    #:with unsafe #'unsafe-unbox*)
+  (pattern (~literal set-box!) #:with unsafe #'unsafe-set-box*!))
+
+(define-syntax-class box-opt-expr
+  (pattern (#%plain-app op:box-op b:box-expr new:expr ...)
+           #:with opt
+           (begin (log-optimization "box" #'op)
+                  #`(op.unsafe b.opt #,@(map (optimize) (syntax->list #'(new ...)))))))
diff --git a/collects/typed-scheme/optimizer/optimizer.rkt b/collects/typed-scheme/optimizer/optimizer.rkt
index 730d6680..d9ad4ab6 100644
--- a/collects/typed-scheme/optimizer/optimizer.rkt
+++ b/collects/typed-scheme/optimizer/optimizer.rkt
@@ -5,7 +5,7 @@
          (for-template scheme/base scheme/flonum scheme/fixnum scheme/unsafe/ops racket/private/for)
          "../utils/utils.rkt"
          (types abbrev type-table utils subtype)
-         (optimizer utils fixnum float inexact-complex vector pair sequence struct dead-code))
+         (optimizer utils fixnum float inexact-complex vector pair sequence box struct dead-code))
 
 (provide optimize-top)
 
@@ -24,6 +24,7 @@
   (pattern e:vector-opt-expr          #:with opt #'e.opt)
   (pattern e:pair-opt-expr            #:with opt #'e.opt)
   (pattern e:sequence-opt-expr        #:with opt #'e.opt)
+  (pattern e:box-opt-expr             #:with opt #'e.opt)
   (pattern e:struct-opt-expr          #:with opt #'e.opt)
   (pattern e:dead-code-opt-expr       #:with opt #'e.opt)
   
diff --git a/collects/typed-scheme/private/base-env.rkt b/collects/typed-scheme/private/base-env.rkt
index 7f865c7a..0ce98a90 100644
--- a/collects/typed-scheme/private/base-env.rkt
+++ b/collects/typed-scheme/private/base-env.rkt
@@ -200,10 +200,18 @@
 [newline (->opt [-Output-Port] -Void)]
 [not (-> Univ B)]
 [box (-poly (a) (a . -> . (-box a)))]
-[unbox (-poly (a) (cl->*                   
+[unbox (-poly (a) (cl->*
                    ((-box a) . -> . a)
                    ((make-BoxTop) . -> . Univ)))]
 [set-box! (-poly (a) ((-box a) a . -> . -Void))]
+[unsafe-unbox (-poly (a) (cl->*
+                          ((-box a) . -> . a)
+                          ((make-BoxTop) . -> . Univ)))]
+[unsafe-set-box! (-poly (a) ((-box a) a . -> . -Void))]
+[unsafe-unbox* (-poly (a) (cl->*
+                           ((-box a) . -> . a)
+                           ((make-BoxTop) . -> . Univ)))]
+[unsafe-set-box*! (-poly (a) ((-box a) a . -> . -Void))]
 [box? (make-pred-ty (make-BoxTop))]
 [cons? (make-pred-ty (-pair Univ Univ))]
 [pair? (make-pred-ty (-pair Univ Univ))]