diff --git a/ANNOUNCE b/ANNOUNCE
index e2a940be9..c27a47f77 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.5.3beta03 - April 3, 2011
+Libpng 1.5.3beta03 - April 17, 2011
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -38,7 +38,21 @@ Version 1.5.3beta02 [April 3, 2011]
   Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
   Optimize the zlib CMF byte in non-IDAT compressed chunks
 
-Version 1.5.3beta03 [April 3, 2011]
+Version 1.5.3beta03 [April 17, 2011]
+  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
+    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
+    than __STDC__ (John Bowler).
+  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
+    the compiler that a user supplied callback (the error handler) does not
+    return, yet there is no guarantee in practice that the application code
+    will correctly implement the error handler because the compiler only
+    issues a warning if there is a mistake (John Bowler).
+  Removed the no-longer-used PNG_DEPSTRUCT macro.
+  Updated the zlib version to 1.2.5 in the VStudio project.
+  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
+    pngwutil.c (John Bowler).
+  Fixed bug with stripping the filler or alpha channel when writing, that
+    was introduced in libpng-1.5.2beta01.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
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diff --git a/CHANGES b/CHANGES
index c634f4911..a86f9a1fa 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3299,7 +3299,21 @@ Version 1.5.3beta02 [April 3, 2011]
   Improved the optimization of the zlib CMF byte (see libpng-1.2.6beta03).
   Optimize the zlib CMF byte in non-IDAT compressed chunks
 
-Version 1.5.3beta03 [April 3, 2011]
+Version 1.5.3beta03 [April 17, 2011]
+  Fixed gcc -ansi -pedantic compile. A strict ANSI system does not have
+    snprintf, and the "__STRICT_ANSI__" detects that condition more reliably
+    than __STDC__ (John Bowler).
+  Removed the PNG_PTR_NORETURN attribute because it too dangerous. It tells
+    the compiler that a user supplied callback (the error handler) does not
+    return, yet there is no guarantee in practice that the application code
+    will correctly implement the error handler because the compiler only
+    issues a warning if there is a mistake (John Bowler).
+  Removed the no-longer-used PNG_DEPSTRUCT macro.
+  Updated the zlib version to 1.2.5 in the VStudio project.
+  Fixed 64-bit builds where png_uint_32 is smaller than png_size_t in
+    pngwutil.c (John Bowler).
+  Fixed bug with stripping the filler or alpha channel when writing, that
+    was introduced in libpng-1.5.2beta01.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngtrans.c b/pngtrans.c
index cf7622cdc..8a536c507 100644
--- a/pngtrans.c
+++ b/pngtrans.c
@@ -1,7 +1,7 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.3 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -442,7 +442,11 @@ png_do_strip_channel(png_row_infop row_info, png_bytep row, int at_start)
    /* At the start sp will point to the first byte to copy and dp to where
     * it is copied to.  ep always points just beyond the end of the row, so
     * the loop simply copies (channels-1) channels until sp reaches ep.
+    *
+    * at_start:  0 -- convert AG, XG, ARGB, XRGB, AAGG, XXGG, etc.
+    *         :  nonzero -- convert GA, GX, RGBA, RGBX, GGAA, RRGGBBXX, etc.
     */
+
    /* GA, GX, XG cases */
    if (row_info->channels == 2)
    {
diff --git a/pngwtran.c b/pngwtran.c
index bbf4a25b9..2473d1406 100644
--- a/pngwtran.c
+++ b/pngwtran.c
@@ -1,7 +1,7 @@
 
 /* pngwtran.c - transforms the data in a row for PNG writers
  *
- * Last changed in libpng 1.5.2 [March 31, 2011]
+ * Last changed in libpng 1.5.3 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -45,7 +45,7 @@ png_do_write_transformations(png_structp png_ptr)
 #ifdef PNG_WRITE_FILLER_SUPPORTED
    if (png_ptr->transformations & PNG_FILLER)
       png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1,
-         !(png_ptr->flags & PNG_FILLER_AFTER));
+         !(png_ptr->flags & PNG_FLAG_FILLER_AFTER));
 #endif
 
 #ifdef PNG_WRITE_PACKSWAP_SUPPORTED