diff --git a/ANNOUNCE b/ANNOUNCE
index 0078e75..bc611c3 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,4 +1,4 @@
-Libpng 1.6.21beta04 - December 29, 2015
+Libpng 1.6.21rc01 - January 4, 2016
 
 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.
@@ -8,20 +8,20 @@
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.6.21beta04.tar.xz (LZMA-compressed, recommended)
-   1.6.21beta04.tar.gz
+   1.6.21rc01.tar.xz (LZMA-compressed, recommended)
+   1.6.21rc01.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   /scratch/glennrp/Libpng16/lp1621b04.7z  (LZMA-compressed, recommended)
-   /scratch/glennrp/Libpng16/lp1621b04.zip
+   /scratch/glennrp/Libpng16/lp1621r01.7z  (LZMA-compressed, recommended)
+   /scratch/glennrp/Libpng16/lp1621r01.zip
 
 Other information:
 
-   1.6.21beta04-README.txt
-   1.6.21beta04-LICENSE.txt
-   libpng-1.6.21beta04-*.asc (armored detached GPG signatures)
+   1.6.21rc01-README.txt
+   1.6.21rc01-LICENSE.txt
+   libpng-1.6.21rc01-*.asc (armored detached GPG signatures)
 
 Changes since the last public release (1.6.20):
 
@@ -51,7 +51,7 @@
   This changes pngvalid to use BE random numbers; this used to produce
     errors but these should not be fixed as a result of the previous changes.
 
-Version 1.6.21beta04 [December 29, 2015]
+Version 1.6.21rc01 [January 4, 2016]
   In projects/vstudio, combined readme.txt and WARNING into README.txt
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
diff --git a/CHANGES b/CHANGES
index 0e597aa..87f854b 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5472,7 +5472,7 @@
   This changes pngvalid to use BE random numbers; this used to produce
     errors but these should not be fixed as a result of the previous changes.
 
-Version 1.6.21beta04 [December 29, 2015]
+Version 1.6.21rc01 [January 4, 2016]
   In projects/vstudio, combined readme.txt and WARNING into README.txt
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 85bb4f4..3a4eba5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -261,7 +261,7 @@
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.21beta04
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.21rc01
     VERSION 16.${PNGLIB_RELEASE}.0
     SOVERSION 16
     CLEAN_DIRECT_OUTPUT 1)
diff --git a/LICENSE b/LICENSE
index 731bf6b..a12126a 100644
--- a/LICENSE
+++ b/LICENSE
@@ -10,8 +10,8 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000, through 1.6.21beta04, December 19, 2015, are
-Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, are
+libpng versions 1.0.7, July 1, 2000, through 1.6.21rc01, January 4, 2016, are
+Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
 added to the list of Contributing Authors:
@@ -109,4 +109,4 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-December 19, 2015
+January 4, 2016
diff --git a/README b/README
index b969f3d..6613b79 100644
--- a/README
+++ b/README
@@ -1,4 +1,4 @@
-README for libpng version 1.6.21beta04 - December 19, 2015 (shared library 16.0)
+README for libpng version 1.6.21rc01 - January 4, 2016 (shared library 16.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
diff --git a/configure.ac b/configure.ac
index 3382a60..709cb02 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,7 +18,7 @@
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.21beta04],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.21rc01],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -39,7 +39,7 @@
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.6.21beta04
+PNGLIB_VERSION=1.6.21rc01
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
 PNGLIB_RELEASE=21
diff --git a/contrib/libtests/pngstest.c b/contrib/libtests/pngstest.c
index 3374c72..0febb63 100644
--- a/contrib/libtests/pngstest.c
+++ b/contrib/libtests/pngstest.c
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2013-2015 John Cunningham Bowler
  *
- * Last changed in libpng 1.6.19 [(PENDING RELEASE)]
+ * Last changed in libpng 1.6.19 [November 12, 2015]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
diff --git a/libpng-manual.txt b/libpng-manual.txt
index 9a24084..09688c6 100644
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -1,9 +1,9 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.21beta04 - December 19, 2015
+ libpng version 1.6.21rc01 - January 4, 2016
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ Copyright (c) 1998-2016 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
  For conditions of distribution and use, see the disclaimer
@@ -11,9 +11,9 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.21beta04 - December 19, 2015
+ libpng versions 0.97, January 1998, through 1.6.21rc01 - January 4, 2016
  Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ Copyright (c) 1998-2016 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6 - version 0.96 - May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -5078,6 +5078,10 @@
 and is interpreted by libpng to convey a one-tracer-curve gray profile or a
 three-tracer-curve RGB profile as appropriate.
 
+Libpng 1.5.x erroneously used /MD for Debug DLL builds; if you used the debug
+builds in your app and you changed your app to use /MD you will need to
+change it back to /MDd for libpng 1.6.x.
+
 Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
 an empty language field or an empty translated keyword.  Both of these
 are allowed by the PNG specification, so these warnings are no longer issued.
@@ -5324,7 +5328,7 @@
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.21beta04 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.21rc01 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has two year fields.  One is a 2-byte unsigned integer
diff --git a/libpng.3 b/libpng.3
index db7ed3c..b0bb7ad 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "December 19, 2015"
+.TH LIBPNG 3 "January 4, 2016"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.21beta04
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.21rc01
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -508,10 +508,10 @@
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.21beta04 - December 19, 2015
+ libpng version 1.6.21rc01 - January 4, 2016
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
- Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ Copyright (c) 1998-2016 Glenn Randers-Pehrson
 
  This document is released under the libpng license.
  For conditions of distribution and use, see the disclaimer
@@ -519,9 +519,9 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.21beta04 - December 19, 2015
+ libpng versions 0.97, January 1998, through 1.6.21rc01 - January 4, 2016
  Updated and distributed by Glenn Randers-Pehrson
- Copyright (c) 1998-2015 Glenn Randers-Pehrson
+ Copyright (c) 1998-2016 Glenn Randers-Pehrson
 
  libpng 1.0 beta 6 - version 0.96 - May 28, 1997
  Updated and distributed by Andreas Dilger
@@ -5586,6 +5586,10 @@
 and is interpreted by libpng to convey a one-tracer-curve gray profile or a
 three-tracer-curve RGB profile as appropriate.
 
+Libpng 1.5.x erroneously used /MD for Debug DLL builds; if you used the debug
+builds in your app and you changed your app to use /MD you will need to
+change it back to /MDd for libpng 1.6.x.
+
 Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
 an empty language field or an empty translated keyword.  Both of these
 are allowed by the PNG specification, so these warnings are no longer issued.
@@ -5832,7 +5836,7 @@
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.21beta04 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.21rc01 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has two year fields.  One is a 2-byte unsigned integer
@@ -5990,7 +5994,7 @@
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.21beta04 - December 19, 2015:
+Libpng version 1.6.21rc01 - January 4, 2016:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6015,8 +6019,8 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.0.7, July 1, 2000, through 1.6.21beta04, December 19, 2015, are
-Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, are
+libpng versions 1.0.7, July 1, 2000, through 1.6.21rc01, January 4, 2016, are
+Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
 derived from libpng-1.0.6, and are distributed according to the same
 disclaimer and license as libpng-1.0.6 with the following individuals
 added to the list of Contributing Authors:
@@ -6114,7 +6118,7 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-December 19, 2015
+January 4, 2016
 
 .\" end of man page
 
diff --git a/libpngpf.3 b/libpngpf.3
index e673699..f679be7 100644
--- a/libpngpf.3
+++ b/libpngpf.3
@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "December 19, 2015"
+.TH LIBPNGPF 3 "January 4, 2016"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.21beta04
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.21rc01
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
diff --git a/png.5 b/png.5
index d6d0048..30e3782 100644
--- a/png.5
+++ b/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "December 19, 2015"
+.TH PNG 5 "January 4, 2016"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
diff --git a/png.c b/png.c
index 4bbc12f..0e17994 100644
--- a/png.c
+++ b/png.c
@@ -14,7 +14,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_21beta04 Your_png_h_is_not_version_1_6_21beta04;
+typedef png_libpng_version_1_6_21rc01 Your_png_h_is_not_version_1_6_21rc01;
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
@@ -775,7 +775,7 @@
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.21beta04 - January 2, 2016" PNG_STRING_NEWLINE \
+      "libpng version 1.6.21rc01 - January 4, 2016" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2015 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
@@ -783,7 +783,7 @@
       "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
       PNG_STRING_NEWLINE;
 #  else
-   return "libpng version 1.6.21beta04 - January 2, 2016\
+   return "libpng version 1.6.21rc01 - January 4, 2016\
       Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
diff --git a/png.h b/png.h
index a887079..88c88bf 100644
--- a/png.h
+++ b/png.h
@@ -1,9 +1,9 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.21beta04, December 19, 2015
+ * libpng version 1.6.21rc01, January 4, 2016
  *
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Copyright (c) 1998-2002,2004,2006-2016 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.)
  *
@@ -12,7 +12,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.21beta04, December 19, 2015:
+ *   libpng versions 0.97, January 1998, through 1.6.21rc01, January 4, 2016:
  *     Glenn Randers-Pehrson.
  *   See also "Contributing Authors", below.
  */
@@ -25,8 +25,8 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.0.7, July 1, 2000, through 1.6.21beta04, December 19, 2015, are
- * Copyright (c) 2000-2002, 2004, 2006-2015 Glenn Randers-Pehrson, are
+ * libpng versions 1.0.7, July 1, 2000, through 1.6.21rc01, January 4, 2016, are
+ * Copyright (c) 2000-2002, 2004, 2006-2016 Glenn Randers-Pehrson, are
  * derived from libpng-1.0.6, and are distributed according to the same
  * disclaimer and license as libpng-1.0.6 with the following individuals
  * added to the list of Contributing Authors:
@@ -214,13 +214,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    December 19, 2015
+ *    January 4, 2016
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.21beta04 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.21rc01 are Y2K compliant.  It is my belief that
  *    earlier versions were also Y2K compliant.
  *
  *    Libpng only has two year fields.  One is a 2-byte unsigned integer
@@ -282,9 +282,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.21beta04"
+#define PNG_LIBPNG_VER_STRING "1.6.21rc01"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.21beta04 - December 19, 2015\n"
+     " libpng version 1.6.21rc01 - January 4, 2016\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -298,7 +298,7 @@
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
-#define PNG_LIBPNG_VER_BUILD  04
+#define PNG_LIBPNG_VER_BUILD  01
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -315,7 +315,7 @@
 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
                                        PNG_LIBPNG_BUILD_PRIVATE */
 
-#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_RC
 
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
@@ -433,7 +433,7 @@
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_6_21beta04;
+typedef char* png_libpng_version_1_6_21rc01;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
diff --git a/pngconf.h b/pngconf.h
index 9345d73..9c7eb82 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.21beta04, December 19, 2015
+ * libpng version 1.6.21rc01, January 4, 2016
  *
  * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
diff --git a/pngpriv.h b/pngpriv.h
index 994d114..e210a01 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -1,7 +1,7 @@
 
 /* pngpriv.h - private declarations for use inside libpng
  *
- * Last changed in libpng 1.6.18 [July 23, 2015]
+ * Last changed in libpng 1.6.21 [(PENDING RELEASE)]
  * Copyright (c) 1998-2002,2004,2006-2015 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.)
diff --git a/pngtest.c b/pngtest.c
index c675480..b440657 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -2070,4 +2070,4 @@
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_21beta04 Your_png_h_is_not_version_1_6_21beta04;
+typedef png_libpng_version_1_6_21rc01 Your_png_h_is_not_version_1_6_21rc01;
diff --git a/projects/vstudio/README.txt b/projects/vstudio/README.txt
index 500e465..4ff9565 100644
--- a/projects/vstudio/README.txt
+++ b/projects/vstudio/README.txt
@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.21beta04 - December 29, 2015
+libpng version 1.6.21rc01 - January 4, 2016
 
 Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson
 
diff --git a/projects/vstudio/zlib.props b/projects/vstudio/zlib.props
index c575e18..a7fffc7 100644
--- a/projects/vstudio/zlib.props
+++ b/projects/vstudio/zlib.props
@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.21beta04 - December 19, 2015
+ * libpng version 1.6.21rc01 - January 4, 2016
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *
diff --git a/scripts/README.txt b/scripts/README.txt
index c0f8635..7dc5fdb 100644
--- a/scripts/README.txt
+++ b/scripts/README.txt
@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.6.21beta04 - December 19, 2015
+Makefiles for  libpng version 1.6.21rc01 - January 4, 2016
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.21beta04)
+                       (gcc, creates libpng16.so.16.1.6.21rc01)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -33,12 +33,12 @@
  makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
  makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng16.so.16.1.6.21beta04)
+                       creates libpng16.so.16.1.6.21rc01)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng16.so.16.1.6.21beta04)
+                       creates libpng16.so.16.1.6.21rc01)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng16.so.16.1.6.21beta04)
+                       creates libpng16.so.16.1.6.21rc01)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile
diff --git a/scripts/def.c b/scripts/def.c
index 0889174..756dc32 100644
--- a/scripts/def.c
+++ b/scripts/def.c
@@ -21,7 +21,7 @@
 PNG_DFN "OS2 CODE PRELOAD MOVEABLE DISCARDABLE"
 PNG_DFN ""
 PNG_DFN "EXPORTS"
-PNG_DFN ";Version 1.6.21beta04"
+PNG_DFN ";Version 1.6.21rc01"
 
 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\
         PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"
diff --git a/scripts/libpng-config-head.in b/scripts/libpng-config-head.in
index 4603742..ee9d2c6 100644
--- a/scripts/libpng-config-head.in
+++ b/scripts/libpng-config-head.in
@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.6.21beta04
+version=1.6.21rc01
 prefix=""
 libdir=""
 libs=""
diff --git a/scripts/libpng.pc.in b/scripts/libpng.pc.in
index 364ef6e..3f665b5 100644
--- a/scripts/libpng.pc.in
+++ b/scripts/libpng.pc.in
@@ -5,6 +5,6 @@
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.6.21beta04
+Version: 1.6.21rc01
 Libs: -L${libdir} -lpng16
 Cflags: -I${includedir}
diff --git a/scripts/makefile.ne12bsd b/scripts/makefile.ne12bsd
index aebbcac..fdd5f24 100644
--- a/scripts/makefile.ne12bsd
+++ b/scripts/makefile.ne12bsd
@@ -17,7 +17,7 @@
 
 LIB=	png16
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.6.21beta04
+SHLIB_MINOR=	1.6.21rc01
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
diff --git a/scripts/makefile.netbsd b/scripts/makefile.netbsd
index ae5d2cd..63fb10b 100644
--- a/scripts/makefile.netbsd
+++ b/scripts/makefile.netbsd
@@ -17,7 +17,7 @@
 
 LIB=	png
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.21beta04
+SHLIB_MINOR=	1.6.21rc01
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
diff --git a/scripts/makefile.openbsd b/scripts/makefile.openbsd
index 05ebb47..a7e453d 100644
--- a/scripts/makefile.openbsd
+++ b/scripts/makefile.openbsd
@@ -11,7 +11,7 @@
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.21beta04
+SHLIB_MINOR=	1.6.21rc01
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \
diff --git a/scripts/pnglibconf.h.prebuilt b/scripts/pnglibconf.h.prebuilt
index d16deab..f2fe1ec 100644
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -1,8 +1,8 @@
-/* libpng 1.6.21beta04 STANDARD API DEFINITION */
+/* libpng 1.6.21rc01 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.21beta04 - December 19, 2015 */
+/* Libpng version 1.6.21rc01 - January 4, 2016 */
 
 /* Copyright (c) 1998-2015 Glenn Randers-Pehrson */
 
diff --git a/scripts/symbols.def b/scripts/symbols.def
index ff3cf2a..3b0e142 100644
--- a/scripts/symbols.def
+++ b/scripts/symbols.def
@@ -1,4 +1,4 @@
-;Version 1.6.21beta04
+;Version 1.6.21rc01
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng