Document patch #512981.
diff --git a/Misc/NEWS b/Misc/NEWS
index 6e2b8f6..a0ead8a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -292,6 +292,9 @@
 Extension modules
 -----------------
 
+- readline now dynamically adjusts its input/output stream if
+  sys.stdin/stdout changes.
+
 - The _tkinter module (and hence Tkinter) has dropped support for
   Tcl/Tk 8.0 and 8.1.  Only Tcl/Tk versions 8.2, 8.3 and 8.4 are
   supported.