diff --git a/collects/mzlib/contract.rkt b/collects/mzlib/contract.rkt
index 01f022f..d38bca4 100644
--- a/collects/mzlib/contract.rkt
+++ b/collects/mzlib/contract.rkt
@@ -47,6 +47,8 @@
          racket/contract/private/misc
          racket/contract/private/provide
          racket/contract/private/guts
+         racket/contract/private/prop
+         racket/contract/private/blame
          racket/contract/private/ds
          racket/contract/private/opt
          racket/contract/private/basic-opters)
@@ -67,7 +69,9 @@
  (rename-out [string-len/c string/len])
  (except-out (all-from-out racket/contract/private/guts)
              check-flat-contract
-             check-flat-named-contract))
+             check-flat-named-contract)
+ (all-from-out racket/contract/private/prop
+               racket/contract/private/blame))
 
 
 ;; copied here because not provided by racket/contract anymore
diff --git a/collects/mzlib/private/contract-arr-checks.rkt b/collects/mzlib/private/contract-arr-checks.rkt
index 19c887a..fbb579d 100644
--- a/collects/mzlib/private/contract-arr-checks.rkt
+++ b/collects/mzlib/private/contract-arr-checks.rkt
@@ -1,7 +1,8 @@
 #lang racket/base
 
 (provide (all-defined-out))
-(require racket/contract/private/guts)
+(require racket/contract/private/guts
+         racket/contract/private/blame)
 
 (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 e42183f..df53d20 100644
--- a/collects/mzlib/private/contract-arr-obj-helpers.rkt
+++ b/collects/mzlib/private/contract-arr-obj-helpers.rkt
@@ -4,7 +4,9 @@
 
 (require (for-syntax scheme/base))
 (require (for-template scheme/base)
-         (for-template racket/contract/private/guts)
+         (for-template racket/contract/private/guts
+                       racket/contract/private/prop
+                       racket/contract/private/blame)
          (for-template "contract-arr-checks.rkt"))
 
 (provide make-/proc ->/h ->*/h ->d/h ->d*/h ->r/h 
diff --git a/collects/mzlib/private/contract-arrow.rkt b/collects/mzlib/private/contract-arrow.rkt
index 34f4d26..13da6f2 100644
--- a/collects/mzlib/private/contract-arrow.rkt
+++ b/collects/mzlib/private/contract-arrow.rkt
@@ -1,6 +1,8 @@
 #lang racket/base
 
 (require racket/contract/private/guts
+         racket/contract/private/blame
+         racket/contract/private/prop
          racket/contract/private/opt
          "contract-arr-checks.rkt")
 (require (for-syntax racket/base)
diff --git a/collects/mzlib/private/contract-mutable.rkt b/collects/mzlib/private/contract-mutable.rkt
index 4e884a4..e6708f8 100644
--- a/collects/mzlib/private/contract-mutable.rkt
+++ b/collects/mzlib/private/contract-mutable.rkt
@@ -4,7 +4,8 @@
          (only-in racket/contract/private/vector
                   vector-immutableof vector-immutable/c)
          racket/contract/private/blame
-         racket/contract/private/guts)
+         racket/contract/private/guts
+         racket/contract/private/prop)
 
 (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 0188cb4..31e4896 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/prop
          racket/private/class-internal
          "contract-arr-checks.rkt")