diff --git a/collects/mzlib/contract.rkt b/collects/mzlib/contract.rkt
index 1ced3d7..68296b6 100644
--- a/collects/mzlib/contract.rkt
+++ b/collects/mzlib/contract.rkt
@@ -37,6 +37,7 @@
 ;;
 
 (require racket/contract/private/base
+         racket/contract/private/vector
          racket/contract/private/misc
          racket/contract/private/provide
          racket/contract/private/guts
@@ -51,6 +52,7 @@
              contract-struct)
  
  (all-from-out racket/contract/private/base)
+ (all-from-out racket/contract/private/vector)
  (all-from-out racket/contract/private/provide)
  (except-out (all-from-out racket/contract/private/misc)
              check-between/c