diff --git a/Doc/library/winsound.rst b/Doc/library/winsound.rst
index 8356062078a..61f34cddc1d 100644
--- a/Doc/library/winsound.rst
+++ b/Doc/library/winsound.rst
@@ -126,6 +126,10 @@ provided by Windows platforms.  It includes functions and several constants.
 
    Return immediately if the sound driver is busy.
 
+   .. note::
+
+      This flag is not supported on modern Windows platforms.
+
 
 .. data:: MB_ICONASTERISK