diff --git a/collects/tests/mred/windowing.ss b/collects/tests/mred/windowing.ss
index 10b0037b..f92de015 100644
--- a/collects/tests/mred/windowing.ss
+++ b/collects/tests/mred/windowing.ss
@@ -265,7 +265,7 @@
     (stv f iconize #t)
     (pause)
     (pause)
-    (st #t f is-iconized?)
+    (st #t f is-iconized?)  ; NB: test will fail on MacOS
     (stv f show #t)
     (pause)
     (st #f f is-iconized?)