diff --git a/collects/typed-scheme/private/type-contract.rkt b/collects/typed-scheme/private/type-contract.rkt
index dd59522a..5c4b9278 100644
--- a/collects/typed-scheme/private/type-contract.rkt
+++ b/collects/typed-scheme/private/type-contract.rkt
@@ -134,7 +134,9 @@
         [(Vector: t)
          #`(vectorof #,(t->c t #:flat #t))]
         [(Box: t)
-         #`(box/c #,(t->c t #:flat #t))]
+         (if flat?
+             #`(box/c #,(t->c t #:flat #t) #:flat? #t)
+             #`(box/c #,(t->c t)))]
         [(Pair: t1 t2)
          #`(cons/c #,(t->c t1) #,(t->c t2))]
         [(Opaque: p? cert)
@@ -206,7 +208,10 @@
         [(Syntax: t) #`(syntax/c #,(t->c t))]
         [(Value: v) #`(flat-named-contract #,(format "~a" v) (lambda (x) (equal? x '#,v)))]
         [(Param: in out) #`(parameter/c #,(t->c out))]
-	[(Hashtable: k v) #`(hash/c #,(t->c k #:flat #t) #,(t->c v #:flat #t) #:immutable 'dont-care)]
+	[(Hashtable: k v) 
+         (if flat?
+             #`(hash/c #,(t->c k #:flat #t) #,(t->c v #:flat #t) #:flat? #t #:immutable 'dont-care)
+             #`(hash/c #,(t->c k) #,(t->c v) #:immutable 'dont-care))]
         [else          
          (exit (fail))]))))