diff --git a/collects/mzlib/contract.rkt b/collects/mzlib/contract.rkt
index de5df8c..b5152e0 100644
--- a/collects/mzlib/contract.rkt
+++ b/collects/mzlib/contract.rkt
@@ -51,7 +51,8 @@
          racket/contract/private/blame
          racket/contract/private/ds
          racket/contract/private/opt
-         racket/contract/private/basic-opters)
+         racket/contract/private/basic-opters
+         racket/contract/combinator)
 
 (provide 
  opt/c define-opt/c ;(all-from "private/contract-opt.rkt")
@@ -70,5 +71,6 @@
              check-flat-contract
              check-flat-named-contract)
  (all-from-out racket/contract/private/prop
-               racket/contract/private/blame))
+               racket/contract/private/blame
+               racket/contract/combinator))
 
diff --git a/collects/mzlib/integer-set.rkt b/collects/mzlib/integer-set.rkt
index 6c14cb1..c32ff58 100644
--- a/collects/mzlib/integer-set.rkt
+++ b/collects/mzlib/integer-set.rkt
@@ -428,7 +428,7 @@
     
   (provide well-formed-set?)
 
-  (provide/contract (struct integer-set ((contents (flat-named-contract "integer-set-list" well-formed-set?))))
+  (provide/contract (struct integer-set ((contents well-formed-set?)))
                     (make-range 
                      (->i () ((i exact-integer?) (j (i) (and/c exact-integer? (>=/c i)))) [res integer-set?]))
                     (rename merge union (integer-set? integer-set? . -> . integer-set?))
diff --git a/collects/mzlib/private/contract-arr-checks.rkt b/collects/mzlib/private/contract-arr-checks.rkt
index fbb579d..1bbf5d5 100644
--- a/collects/mzlib/private/contract-arr-checks.rkt
+++ b/collects/mzlib/private/contract-arr-checks.rkt
@@ -2,7 +2,8 @@
 
 (provide (all-defined-out))
 (require racket/contract/private/guts
-         racket/contract/private/blame)
+         racket/contract/private/blame
+         racket/contract/private/misc)
 
 (define empty-case-lambda/c
   (flat-named-contract '(case->)
diff --git a/collects/mzlib/private/contract-arr-obj-helpers.rkt b/collects/mzlib/private/contract-arr-obj-helpers.rkt
index df53d20..d72c58c 100644
--- a/collects/mzlib/private/contract-arr-obj-helpers.rkt
+++ b/collects/mzlib/private/contract-arr-obj-helpers.rkt
@@ -5,6 +5,7 @@
 (require (for-syntax scheme/base))
 (require (for-template scheme/base)
          (for-template racket/contract/private/guts
+                       racket/contract/private/misc
                        racket/contract/private/prop
                        racket/contract/private/blame)
          (for-template "contract-arr-checks.rkt"))
diff --git a/collects/mzlib/private/contract-arrow.rkt b/collects/mzlib/private/contract-arrow.rkt
index 13da6f2..6471de6 100644
--- a/collects/mzlib/private/contract-arrow.rkt
+++ b/collects/mzlib/private/contract-arrow.rkt
@@ -4,6 +4,7 @@
          racket/contract/private/blame
          racket/contract/private/prop
          racket/contract/private/opt
+         racket/contract/private/misc
          "contract-arr-checks.rkt")
 (require (for-syntax racket/base)
          (for-syntax racket/contract/private/opt-guts)
diff --git a/collects/mzlib/private/contract-mutable.rkt b/collects/mzlib/private/contract-mutable.rkt
index e6708f8..ca1670f 100644
--- a/collects/mzlib/private/contract-mutable.rkt
+++ b/collects/mzlib/private/contract-mutable.rkt
@@ -5,7 +5,8 @@
                   vector-immutableof vector-immutable/c)
          racket/contract/private/blame
          racket/contract/private/guts
-         racket/contract/private/prop)
+         racket/contract/private/prop
+         racket/contract/private/misc)
 
 (provide box/c box-immutable/c
          vector/c vectorof vector-immutableof vector-immutable/c)
diff --git a/collects/mzlib/private/contract-object.rkt b/collects/mzlib/private/contract-object.rkt
index 31e4896..57b9ee0 100644
--- a/collects/mzlib/private/contract-object.rkt
+++ b/collects/mzlib/private/contract-object.rkt
@@ -1,6 +1,7 @@
 #lang racket/base
 (require "contract-arrow.rkt"
          racket/contract/private/guts
+         racket/contract/private/misc
          racket/contract/private/prop
          racket/private/class-internal
          "contract-arr-checks.rkt")
diff --git a/collects/mzlib/private/contract-struct.rkt b/collects/mzlib/private/contract-struct.rkt
index 55d5d03..42af731 100644
--- a/collects/mzlib/private/contract-struct.rkt
+++ b/collects/mzlib/private/contract-struct.rkt
@@ -3,7 +3,8 @@
 (require (for-syntax racket/base
                      racket/contract/private/helpers
                      racket/struct-info)
-         racket/contract/private/guts)
+         racket/contract/private/guts
+         racket/contract/private/misc)
 
 (provide struct/c)
 
diff --git a/collects/mzlib/unit.rkt b/collects/mzlib/unit.rkt
index 0f93d85..a18a36e 100644
--- a/collects/mzlib/unit.rkt
+++ b/collects/mzlib/unit.rkt
@@ -17,6 +17,8 @@
   
 (require mzlib/etc
          racket/contract/base
+         racket/contract/region
+         racket/contract/combinator
          scheme/stxparam
          syntax/location
          "private/unit-contract.rkt"