diff --git a/png.c b/png.c
index 18d26db8..931a8fc6 100644
--- a/png.c
+++ b/png.c
@@ -1,7 +1,7 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.2.46 [February 25, 2011]
+ * Last changed in libpng 1.2.51 [February 25, 2011]
  * 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.)
@@ -17,7 +17,7 @@
 #include "png.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_2_50 Your_png_h_is_not_version_1_2_50;
+typedef version_1_2_51beta01 Your_png_h_is_not_version_1_2_51beta01;
 
 /* Version information for C files.  This had better match the version
  * string defined in png.h.
@@ -724,14 +724,14 @@ png_get_copyright(png_structp png_ptr)
 #else
 #ifdef __STDC__
    return ((png_charp) PNG_STRING_NEWLINE \
-     "libpng version 1.2.50 - July 10, 2012" PNG_STRING_NEWLINE \
-     "Copyright (c) 1998-2011 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
+     "libpng version 1.2.51beta01 - January 1, 2013" PNG_STRING_NEWLINE \
+     "Copyright (c) 1998-2013 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE);
 #else
-      return ((png_charp) "libpng version 1.2.50 - July 10, 2012\
-      Copyright (c) 1998-2011 Glenn Randers-Pehrson\
+      return ((png_charp) "libpng version 1.2.51beta01 - January 1, 2013\
+      Copyright (c) 1998-2013 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.");
 #endif
diff --git a/png.h b/png.h
index 35609691..644bde71 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.2.50 - July 10, 2012
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * libpng version 1.2.51beta01 - January 1, 2013
+ * Copyright (c) 1998-2013 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.)
  *
@@ -10,7 +10,7 @@
  * Authors and maintainers:
  *  libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *  libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *  libpng versions 0.97, January 1998, through 1.2.50 - July 10, 2012: Glenn
+ *  libpng versions 0.97, January 1998, through 1.2.51beta01 - January 1, 2013: Glenn
  *  See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -284,6 +284,7 @@
  *    1.2.49                  13    10249  12.so.0.49[.0]
  *    1.0.60                  10    10060  10.so.0.60[.0]
  *    1.2.50                  13    10250  12.so.0.50[.0]
+ *    1.2.51beta01            13    10251  12.so.0.51[.0]
  *
  *    Henceforth the source version will match the shared-library major
  *    and minor numbers; the shared-library major version number will be
@@ -315,7 +316,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.2.50, July 10, 2012, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.2.51beta01, January 1, 2013, are
  * Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -427,13 +428,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    July 10, 2012
+ *    January 1, 2013
  *
  *    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 1.2.50 are Y2K compliant.  It is my belief that earlier
+ *    upward through 1.2.51beta01 are Y2K compliant.  It is my belief that earlier
  *    versions were also Y2K compliant.
  *
  *    Libpng only has three year fields.  One is a 2-byte unsigned integer
@@ -489,9 +490,9 @@
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.2.50"
+#define PNG_LIBPNG_VER_STRING "1.2.51beta01"
 #define PNG_HEADER_VERSION_STRING \
-   " libpng version 1.2.50 - July 10, 2012\n"
+   " libpng version 1.2.51beta01 - January 1, 2013\n"
 
 #define PNG_LIBPNG_VER_SONUM   0
 #define PNG_LIBPNG_VER_DLLNUM  13
@@ -499,12 +500,12 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   2
-#define PNG_LIBPNG_VER_RELEASE 50
+#define PNG_LIBPNG_VER_RELEASE 51
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
  */
 
-#define PNG_LIBPNG_VER_BUILD  0
+#define PNG_LIBPNG_VER_BUILD  01
 
 /* Release Status */
 #define PNG_LIBPNG_BUILD_ALPHA    1
@@ -521,7 +522,7 @@
 #define PNG_LIBPNG_BUILD_SPECIAL 32 /* Cannot be OR'ed with
                                        PNG_LIBPNG_BUILD_PRIVATE */
 
-#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_STABLE
+#define PNG_LIBPNG_BUILD_BASE_TYPE PNG_LIBPNG_BUILD_BETA
 
 /* Careful here.  At one time, Guy wanted to use 082, but that would be octal.
  * We must not include leading zeros.
@@ -529,7 +530,7 @@
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10250 /* 1.2.50 */
+#define PNG_LIBPNG_VER 10251 /* 1.2.51 */
 
 #ifndef PNG_VERSION_INFO_ONLY
 /* Include the compression library's header */
@@ -1569,7 +1570,7 @@ struct png_struct_def
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef png_structp version_1_2_50;
+typedef png_structp version_1_2_51beta01;
 
 typedef png_struct FAR * FAR * png_structpp;
 
diff --git a/pngconf.h b/pngconf.h
index 042a5e98..9952be1d 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,8 +1,8 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.2.50 - July 10, 2012
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * libpng version 1.2.51beta01 - January 1, 2013
+ * Copyright (c) 1998-2013 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/pngset.c b/pngset.c
index 1d6b10bc..dca247a7 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1,8 +1,8 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.2.51 [December 10, 2012]
- * Copyright (c) 1998-2012 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.51 [January 1, 2013]
+ * Copyright (c) 1998-2013 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 ccb3dce7..8c6ff79e 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1702,4 +1702,4 @@ main(int argc, char *argv[])
 }
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef version_1_2_50 your_png_h_is_not_version_1_2_50;
+typedef version_1_2_51beta01 your_png_h_is_not_version_1_2_51beta01;