mangle keyword-only argname when loading defaults (closes #14607)
diff --git a/Misc/NEWS b/Misc/NEWS
index adb0b08..2c13563 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,8 @@
 Core and Builtins
 -----------------
 
+- Issue #14607: Fix defaults keyword-only arguments which started with ``__``.
+
 - Issue #13889: Check and (if necessary) set FPU control word before calling
   any of the dtoa.c string <-> float conversion functions, on MSVC builds of
   Python.  This fixes issues when embedding Python in a Delphi app.