diff --git a/ANNOUNCE b/ANNOUNCE
index 3c2050442..ceaba0a80 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -35,6 +35,9 @@ Version 1.6.23beta01 [May 29, 2016]
     (John Bowler).
 
 Version 1.6.23beta02 [May 29, 2016]
+  Corrected progressive read input buffer in pngvalid.c. The previous version
+    the code invariably passed just one byte at a time to libpng.  The intent
+    was to pass a random number of bytes in the range 0..511.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 10cf81533..77dced719 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5583,6 +5583,9 @@ Version 1.6.23beta01 [May 29, 2016]
     (John Bowler).
 
 Version 1.6.23beta02 [May 29, 2016]
+  Corrected progressive read input buffer in pngvalid.c. The previous version
+    the code invariably passed just one byte at a time to libpng.  The intent
+    was to pass a random number of bytes in the range 0..511.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 60bde8d6c..8b8fbda8d 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -1,7 +1,7 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.22 [May 26, 2016]
+ * Last changed in libpng 1.6.23 [(PENDING RELEASE)]
  * Copyright (c) 2014-2016 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *