diff --git a/collects/scheme/generator.ss b/collects/scheme/generator.ss
index a59bf9414e..b9a9e83737 100644
--- a/collects/scheme/generator.ss
+++ b/collects/scheme/generator.ss
@@ -6,9 +6,9 @@
 
 (provide yield generator in-generator)
 
-(define-syntax-parameter yield
-  (lambda (stx)
-    (raise-syntax-error #f "yield is only bound inside a sequence generator")))
+;; (define-syntax-parameter yield
+;;   (lambda (stx)
+;;     (raise-syntax-error #f "yield is only bound inside a sequence generator")))
 
 ;; (define (procedure->generator proc)
 ;;   (define tag (make-continuation-prompt-tag))
@@ -20,18 +20,44 @@
 ;;         r)))
 ;;   (lambda () (cont)))
 
+(define current-yielder
+  (make-parameter
+   (lambda (v)
+     (error 'yield "yield cannot be called when no generator is active"))))
+
+(define (yield value)
+  ((current-yielder) value))
+
+(define yield-tag (make-continuation-prompt-tag))
+
+(define-syntax-rule (generator body0 body ...)
+  (let ()
+    (define (cont)
+      (define (yielder value)
+        (shift-at yield-tag k (set! cont k) value))
+      (reset-at yield-tag
+                (parameterize ([current-yielder yielder])
+                  (let ([retval (begin body0 body ...)])
+                    ;; normal return:
+                    (set! cont (lambda () retval))
+                    retval))))
+    (define (generator) (cont))
+    generator))
+
+;; not using parameterization
+#;
 (define-syntax-rule (generator body0 body ...)
   (let ([tag (make-continuation-prompt-tag)])
     (define yielder
       (let ([yield (lambda (value) (shift-at tag k (set! cont k) value))])
         yield))
     (splicing-syntax-parameterize ([yield (make-rename-transformer #'yielder)])
-      (define (cont)
-        (reset-at tag
-          (let ([retval (begin body0 body ...)])
-            ;; normal return:
-            (set! cont (lambda () retval))
-            retval))))
+                                  (define (cont)
+                                    (reset-at tag
+                                              (let ([retval (begin body0 body ...)])
+                                                ;; normal return:
+                                                (set! cont (lambda () retval))
+                                                retval))))
     (define (generator) (cont))
     generator))
 
diff --git a/collects/tests/mzscheme/for.ss b/collects/tests/mzscheme/for.ss
index 8084d4ad03..dbb5b4973f 100644
--- a/collects/tests/mzscheme/for.ss
+++ b/collects/tests/mzscheme/for.ss
@@ -222,4 +222,22 @@
       (for/list ([(x i) (in-indexed (in-generator (yield 1) (yield 2) (yield 3)))])
         (list x i)))
 
+(let ([helper (lambda (i)
+                (yield (add1 i)))])
+  (test '(1 2 3) 'parameterized-yield
+        (for/list ([x (in-generator (helper 0) (helper 1) (helper 2))])
+                  x)))
+
+(let* ([helper (lambda (pred num)
+                 (for ([i (in-range 0 3)])
+                      (yield (pred (+ i num)))))]
+       [g1 (generator
+             (helper odd? 1)
+             (yield 'odd))]
+       [g2 (generator
+             (helper even? 1)
+             (yield 'even))])
+  (test '(#t #f #f #t #t #f odd even) 'yield-helper
+        (list (g1) (g2) (g1) (g2) (g1) (g2) (g1) (g2))))
+
 (report-errs)