diff --git a/racketmq/private/util.rkt b/racketmq/private/util.rkt
index 41f7fe0..d8a0d68 100644
--- a/racketmq/private/util.rkt
+++ b/racketmq/private/util.rkt
@@ -64,13 +64,13 @@
   (define-values (resp response-body)
     (react/suspend (k)
       (on-start
-       (printf "~a --> ~a ~a ~v\n" req-id verb urlstr request-body)
+       (log-info "~a --> ~a ~a ~v" req-id verb urlstr request-body)
        (send! (web-request req-id
                            'outbound
                            (web-request-header verb res headers (url-query u))
                            request-body)))
       (stop-when (message (web-response-complete req-id $resp $response-body))
-                 (printf "~a <-- ~v ~v\n" req-id resp response-body)
+                 (log-info "~a <-- ~v ~v" req-id resp response-body)
                  (k resp response-body))))
   (define location (and resp (dict-ref (web-response-header-headers resp) 'location #f)))
   (if (and resp