#6509: fix re.sub to work properly when the pattern, the string, and the replacement were all bytes. Patch by Antoine Pitrou.
diff --git a/Misc/NEWS b/Misc/NEWS
index 0aaf558..12a8f38 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -268,6 +268,9 @@
 Library
 -------
 
+- Issue #6509: fix re.sub to work properly when the pattern, the string, and
+  the replacement were all bytes. Patch by Antoine Pitrou.
+
 - The sqlite3 module was updated to pysqlite 2.6.0. This fixes several obscure
   bugs and allows loading SQLite extensions from shared libraries.