diff --git a/collects/mzlib/port.ss b/collects/mzlib/port.ss
index df1cd9b..56b1203 100644
--- a/collects/mzlib/port.ss
+++ b/collects/mzlib/port.ss
@@ -2,7 +2,7 @@
 
 (require (for-syntax scheme/base)
          mzlib/etc
-         scheme/contract
+         scheme/contract/base
          mzlib/list
          "private/port.ss")
 
diff --git a/collects/mzlib/private/contract-define.ss b/collects/mzlib/private/contract-define.ss
index cf76531..4cece1f 100644
--- a/collects/mzlib/private/contract-define.ss
+++ b/collects/mzlib/private/contract-define.ss
@@ -5,7 +5,7 @@
 (require (for-syntax scheme/base
                      unstable/srcloc
                      (prefix-in a: scheme/contract/private/helpers))
-         (only-in scheme/contract contract))
+         (only-in scheme/contract/private/base contract))
 
 ;; First, we have the old define/contract implementation, which
 ;; is still used in mzlib/contract.