diff --git a/collects/scheme/match/define-forms.ss b/collects/scheme/match/define-forms.ss
index d1967c5845..a75643183d 100644
--- a/collects/scheme/match/define-forms.ss
+++ b/collects/scheme/match/define-forms.ss
@@ -36,14 +36,15 @@
      
      (define-syntax (match-lambda** stx)
        (syntax-case stx ()
-         [(k [(pats ...) . rhs] ...)
-          (let* ([pss (syntax->list #'((pats ...) ...))]
-                 [len (length (syntax->list (car pss)))])
+         [(k [pats . rhs] ...)
+          (let* ([pss (syntax->list #'(pats ...))]
+                 [ps1 (car pss)]
+                 [len (length (syntax->list ps1))])
             (for/list ([ps pss])
                       (unless (= (length (syntax->list ps)) len)
-                        (raise-syntax-error 'match "unequal number of patterns in match clauses" stx ps)))
+                        (raise-syntax-error 'match "unequal number of patterns in match clauses" stx ps ps1)))
             (with-syntax ([(vars ...) (generate-temporaries (car pss))])
-              (syntax/loc stx (lambda (vars ...) (match* (vars ...) [(pats ...) . rhs] ...)))))]))
+              (syntax/loc stx (lambda (vars ...) (match* (vars ...) [pats . rhs] ...)))))]))
      
      
      
diff --git a/collects/scheme/match/parse-helper.ss b/collects/scheme/match/parse-helper.ss
index e80b4acbba..c23bd62836 100644
--- a/collects/scheme/match/parse-helper.ss
+++ b/collects/scheme/match/parse-helper.ss
@@ -8,12 +8,32 @@
          "compiler.ss"
          (only-in srfi/1 delete-duplicates))
 
-(provide ddk? parse-literal all-vars pattern-var? match:syntax-err
-         matchable?)
+(provide ddk? parse-literal all-vars pattern-var? match:syntax-err match-expander-transform matchable?)
+
+;; transform a match-expander application
+;; parse/cert : stx certifier -> pattern
+;; cert : certifier
+;; expander : identifier
+;; stx : the syntax of the match-expander application
+;; accessor : match-expander -> syntax transformer/#f
+;; error-msg : string
+;; produces a parsed pattern
+(define (match-expander-transform parse/cert cert expander stx accessor error-msg)  
+  (let* ([expander (syntax-local-value (cert expander))]
+         [transformer (accessor expander)])   
+    (unless transformer (raise-syntax-error #f error-msg #'expander))
+    (let* ([introducer (make-syntax-introducer)]
+           [certifier (match-expander-certifier expander)]
+           [mstx (introducer (syntax-local-introduce stx))]
+           [mresult (transformer mstx)]
+           [result (syntax-local-introduce (introducer mresult))]
+           [cert* (lambda (id) (certifier (cert id) #f introducer))])
+      (parse/cert result cert*))))
 
 (define (matchable? e)
   (or (string? e) (bytes? e)))
 
+
 ;; raise an error, blaming stx
 (define (match:syntax-err stx msg)
   (raise-syntax-error #f msg stx))
diff --git a/collects/scheme/match/parse-legacy.ss b/collects/scheme/match/parse-legacy.ss
index 7cd585bfdb..bfff1639cb 100644
--- a/collects/scheme/match/parse-legacy.ss
+++ b/collects/scheme/match/parse-legacy.ss
@@ -18,21 +18,12 @@
     (lambda (x y) (eq? (syntax-e x) (syntax-e y)))
     
     [(expander args ...)
-       (and (identifier? #'expander)
-            ;; for debugging
-            (syntax-transforming?)
-            (match-expander? (syntax-local-value (cert #'expander) (lambda () #f))))
-       (let* ([expander (syntax-local-value (cert #'expander))]
-              [transformer (match-expander-legacy-xform expander)])
-         (unless transformer
-           (raise-syntax-error #f "This expander only works with the standard match syntax" #'expander))
-         (let* ([introducer (make-syntax-introducer)]
-                [certifier (match-expander-certifier expander)]
-                [mstx (introducer (syntax-local-introduce stx))]
-                [mresult (transformer mstx)]
-                [result (syntax-local-introduce (introducer mresult))]
-                [cert* (lambda (id) (certifier (cert id) #f introducer))])
-           (parse/legacy/cert result cert*)))]
+     (and (identifier? #'expander)
+          ;; for debugging
+          (syntax-transforming?)
+          (match-expander? (syntax-local-value (cert #'expander) (lambda () #f))))
+     (match-expander-transform parse/legacy/cert cert #'expander stx match-expander-legacy-xform 
+                               "This expander only works with the standard match syntax")]
     [(and p ...)
      (make-And (map parse (syntax->list #'(p ...))))]
     [(or p ...)
diff --git a/collects/scheme/match/parse.ss b/collects/scheme/match/parse.ss
index e430aee5c2..fddf182cd0 100644
--- a/collects/scheme/match/parse.ss
+++ b/collects/scheme/match/parse.ss
@@ -22,19 +22,10 @@
     (lambda (x y) (eq? (syntax-e x) (syntax-e y)))
     
     [(expander args ...)
-       (and (identifier? #'expander)
-            (match-expander? (syntax-local-value (cert #'expander) (lambda () #f))))
-       (let* ([expander (syntax-local-value (cert #'expander))]
-              [transformer (match-expander-match-xform expander)])
-         (unless transformer
-           (raise-syntax-error #f "This expander only works with the legacy match syntax" #'expander))
-         (let* ([introducer (make-syntax-introducer)]
-                [certifier (match-expander-certifier expander)]
-                [mstx (introducer (syntax-local-introduce stx))]
-                [mresult (transformer mstx)]
-                [result (syntax-local-introduce (introducer mresult))]
-                [cert* (lambda (id) (certifier (cert id) #f introducer))])
-           (parse/cert result cert*)))]
+     (and (identifier? #'expander)
+          (match-expander? (syntax-local-value (cert #'expander) (lambda () #f))))
+     (match-expander-transform parse/cert cert #'expander stx match-expander-match-xform 
+                                 "This expander only works with the legacy match syntax")]
     [(var v)
      (identifier? #'v)
      (make-Var #'v)]