diff --git a/collects/mzlib/private/unit-contract-syntax.ss b/collects/mzlib/private/unit-contract-syntax.ss
index ad6e269f24..88de84cd48 100644
--- a/collects/mzlib/private/unit-contract-syntax.ss
+++ b/collects/mzlib/private/unit-contract-syntax.ss
@@ -1,7 +1,8 @@
 #lang scheme/base
 
-(require stxclass
+(require syntax/parse
          "unit-compiletime.ss"
+         "unit-keywords.ss"
          (for-template "unit-keywords.ss"))
 
 (provide import-clause/contract export-clause/contract dep-clause
@@ -10,9 +11,9 @@
 (define-syntax-class sig-id
   #:attributes ()
   (pattern x
-           #:declare x (static-of 'signature 
-                                  (λ (x)
-                                    (signature? (set!-trans-extract x))))))
+           #:declare x (static (λ (x)
+                                 (signature? (set!-trans-extract x)))
+                               'signature)))
 
 (define-syntax-class sig-spec #:literals (prefix rename only except)
   #:attributes ((name 0))
@@ -28,6 +29,7 @@
            #:with name #'s.name))
 
 (define-syntax-class tagged-sig-spec #:literals (tag)
+  #:auto-nested-attributes
   #:transparent
   (pattern s:sig-spec
            #:with i #f)
@@ -40,30 +42,37 @@
   (pattern (tag i:identifier s:sig-id)))
 
 (define-syntax-class unit/c-clause
+  #:auto-nested-attributes
   #:transparent
   (pattern (s:tagged-sig-id [x:identifier c:expr] ...))
   (pattern s:tagged-sig-id ;; allow a non-wrapped sig, which is the same as (sig)
            #:with (x ...) null
            #:with (c ...) null))
 (define-syntax-class import-clause/c #:literals (import)
+  #:auto-nested-attributes
   #:transparent
   (pattern (import i:unit/c-clause ...)))
 (define-syntax-class export-clause/c #:literals (export)
+  #:auto-nested-attributes
   #:transparent
   (pattern (export e:unit/c-clause ...)))
 
 (define-syntax-class unit/contract-clause
+  #:auto-nested-attributes
   #:transparent
   (pattern (s:tagged-sig-spec [x:identifier c:expr] ...))
   (pattern s:tagged-sig-spec ;; allow a non-wrapped sig, which is the same as (sig)
            #:with (x ...) null
            #:with (c ...) null))
 (define-syntax-class import-clause/contract #:literals (import)
+  #:auto-nested-attributes
   #:transparent
   (pattern (import i:unit/contract-clause ...)))
 (define-syntax-class export-clause/contract #:literals (export)
+  #:auto-nested-attributes
   #:transparent
   (pattern (export e:unit/contract-clause ...)))
 (define-syntax-class dep-clause #:literals (init-depend)
+  #:auto-nested-attributes
   #:transparent
   (pattern (init-depend s:tagged-sig-id ...)))
diff --git a/collects/mzlib/private/unit-contract.ss b/collects/mzlib/private/unit-contract.ss
index 428b80b61b..a3b4598bc2 100644
--- a/collects/mzlib/private/unit-contract.ss
+++ b/collects/mzlib/private/unit-contract.ss
@@ -1,12 +1,13 @@
 #lang scheme/base
 
 (require (for-syntax scheme/base
-                     stxclass
                      syntax/boundmap
                      syntax/name
+                     syntax/parse
                      "unit-compiletime.ss"
                      "unit-contract-syntax.ss"
                      "unit-syntax.ss")
+         (for-meta 2 scheme/base)
          scheme/contract
          "unit-utils.ss"
          "unit-runtime.ss")
diff --git a/collects/mzlib/unit.ss b/collects/mzlib/unit.ss
index fcca03b84e..61be0f6786 100644
--- a/collects/mzlib/unit.ss
+++ b/collects/mzlib/unit.ss
@@ -1,10 +1,10 @@
 (module unit mzscheme
   (require-for-syntax mzlib/list
-                      stxclass
                       syntax/boundmap
                       syntax/context
                       syntax/kerncase
                       syntax/name
+                      syntax/parse
                       syntax/struct
                       syntax/stx
                       "private/unit-contract-syntax.ss"