diff --git a/racket-webview.rkt b/racket-webview.rkt
index 3c8387d..29b0a38 100644
--- a/racket-webview.rkt
+++ b/racket-webview.rkt
@@ -1037,7 +1037,7 @@
       (set! value-set-at (current-milliseconds))
       (when (eq? wait-thread #f)
         (thread (λ ()
-                  (let loop () ((vsa value-set-at))
+                  (let loop ((vsa value-set-at))
                     (sleep seconds)
                     (let ((cms (current-milliseconds)))
                       (if (>= (- cms vsa) ms)