diff --git a/collects/web-server/prototype-web-server/private/stuff-url.ss b/collects/web-server/prototype-web-server/private/stuff-url.ss
index 9007f6f8d1..4a4f732936 100644
--- a/collects/web-server/prototype-web-server/private/stuff-url.ss
+++ b/collects/web-server/prototype-web-server/private/stuff-url.ss
@@ -8,6 +8,7 @@
   ; XXX different ways to hash, different ways to store (maybe cookie?)
     
   (provide stuff-url
+           stuffed-url?
            extend-url-query
            unstuff-url)
   
@@ -36,6 +37,12 @@
       (error "the url is too big: " (url->string result-uri)))
     result-uri)
   
+  (define (stuffed-url? uri)
+    (let* ([qry (url-query uri)]
+           [l-code (find-binding 'c qry)])
+      (and l-code
+           #t)))
+  
   (define (extend-url-query uri key val)
     (make-url
      (url-scheme uri)
diff --git a/collects/web-server/prototype-web-server/private/web.ss b/collects/web-server/prototype-web-server/private/web.ss
index a013739839..f0d4f10783 100644
--- a/collects/web-server/prototype-web-server/private/web.ss
+++ b/collects/web-server/prototype-web-server/private/web.ss
@@ -90,10 +90,8 @@
     (or
      ; Look in url for c=<k>
      (let* ([ses (current-session)]
-            [req-url (request-uri req)]
-            [qry (url-query req-url)]
-            [l-code (find-binding 'c qry)])
-       (and l-code
+            [req-url (request-uri req)])
+       (and (stuffed-url? req-url)
             (deserialize
              (unstuff-url
               req-url (session-url ses)