diff --git a/functional-tests/utils.scm b/functional-tests/utils.scm
index c47b43b..d50358b 100644
--- a/functional-tests/utils.scm
+++ b/functional-tests/utils.scm
@@ -2,7 +2,8 @@
   (utils)
   (export inc!
           dec!
-          swap!)
+          swap!
+          fluid-let)
   (import (rnrs))
 
   (define-syntax inc!
@@ -21,4 +22,16 @@
        (let ((tmp x))
         (set! x y)
         (set! y tmp)))))
+
+  (define-syntax fluid-let
+    (syntax-rules ()
+      ((_ ((x e)) b1 b2 ...)
+       (let ((y e))
+        (let ((swap (lambda ()
+                      (let ((t x))
+                       (set! x y)
+                       (set! y t)))))
+          (dynamic-wind swap (lambda ()
+                               b1 b2 ...)
+                        swap))))))
   )