diff --git a/collects/sgl/examples/gl-frame.rkt b/collects/sgl/examples/gl-frame.rkt
index 4a5fc79621..59d098d2bc 100644
--- a/collects/sgl/examples/gl-frame.rkt
+++ b/collects/sgl/examples/gl-frame.rkt
@@ -70,7 +70,7 @@
              (set! init? #t))
            (gl-draw)
            (swap-gl-buffers)))
-        (refresh))
+        (queue-callback (lambda () (refresh)) #f))
       
       (define/override (on-size w h)
         (with-gl-context