diff --git a/collects/mzlib/etc.ss b/collects/mzlib/etc.ss
index 7b15358..23d656c 100644
--- a/collects/mzlib/etc.ss
+++ b/collects/mzlib/etc.ss
@@ -5,7 +5,8 @@
            (only scheme/base 
                  build-string
                  build-list
-                 build-vector)
+                 build-vector
+                 compose)
            "kw.ss")
 
   (require-for-syntax (lib "kerncase.ss" "syntax")
@@ -53,29 +54,6 @@
 
   (define identity (lambda (x) x))
 
-  (define compose
-    (case-lambda
-      [(f) (if (procedure? f) f (raise-type-error 'compose "procedure" f))]
-      [(f g)
-       (let ([f (compose f)]
-             [g (compose g)])
-         (if (eqv? 1 (procedure-arity f)) ; optimize: don't use call-w-values
-             (if (eqv? 1 (procedure-arity g)) ; optimize: single arity everywhere
-                 (lambda (x) (f (g x)))
-                 (lambda args (f (apply g args))))
-             (if (eqv? 1 (procedure-arity g)) ; optimize: single input
-                 (lambda (a)
-                   (call-with-values
-                    (lambda () (g a))
-                    f))
-                 (lambda args
-                   (call-with-values
-                    (lambda () (apply g args))
-                    f)))))]
-      [(f . more)
-       (let ([m (apply compose more)])
-         (compose f m))]))
-
   (define (loop-until start done? next body)
     (let loop ([i start])
       (unless (done? i)