diff --git a/Misc/NEWS b/Misc/NEWS
index 2837ef9..ff469e7 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -339,6 +339,8 @@
 Library
 -------
 
+- Issue #8546: Reject None given as the buffering argument to _pyio.open.
+
 - Issue #8549: Fix compiling the _ssl extension under AIX.  Patch by
   Sridhar Ratnakumar.