diff --git a/ANNOUNCE b/ANNOUNCE
index 97342e8df..186f2730e 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -471,6 +471,7 @@ Version 1.7.0beta25 [December 26, 2013]
 Version 1.7.0beta26 [December 27, 2013]
   Added libpng 1.5 checks to pngvalid.c
   Merged with 1.5 and 1.6 changes to create a single pngvalid.c
+  Added dSIG to chunk list in png.h
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
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diff --git a/CHANGES b/CHANGES
index 38226f689..59c024431 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4760,6 +4760,7 @@ Version 1.7.0beta25 [December 26, 2013]
 Version 1.7.0beta26 [December 27, 2013]
   Added libpng 1.5 checks to pngvalid.c
   Merged with 1.5 and 1.6 changes to create a single pngvalid.c
+  Added dSIG to chunk list in png.h
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/png.h b/png.h
index 951de043a..6156326f2 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.7.0beta26 - December 26, 2013
+ * libpng version 1.7.0beta26 - December 27, 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.)
@@ -11,7 +11,7 @@
  * 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 1.7.0beta26 - December 26, 2013: Glenn
+ *   libpng versions 0.97, January 1998, through 1.7.0beta26 - December 27, 2013: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -200,7 +200,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.7.0beta26, December 26, 2013, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.7.0beta26, December 27, 2013, are
  * Copyright (c) 2004, 2006-2013 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:
@@ -312,7 +312,7 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    December 26, 2013
+ *    December 27, 2013
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
@@ -380,7 +380,7 @@
 /* Version information for png.h - this should match the version in png.c */
 #define PNG_LIBPNG_VER_STRING "1.7.0beta26"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.7.0beta26 - December 26, 2013\n"
+     " libpng version 1.7.0beta26 - December 27, 2013\n"
 
 #define PNG_LIBPNG_VER_SONUM   17
 #define PNG_LIBPNG_VER_DLLNUM  17
@@ -543,6 +543,10 @@
  *
  * In 1.7.0 the definitions were made public in png.h to avoid having to
  * duplicate the same definitions in application code.
+ *
+ * SOURCE: http://www.libpng.org/pub/png/spec/register/
+ *    "Register of PNG Public Chunks and Keywords, version 1.4.6"
+ *    "Extensions to the PNG Specification, version 1.4.0"
  */
 #define png_IDAT PNG_U32( 73,  68,  65,  84)
 #define png_IEND PNG_U32( 73,  69,  78,  68)
@@ -550,6 +554,7 @@
 #define png_PLTE PNG_U32( 80,  76,  84,  69)
 #define png_bKGD PNG_U32( 98,  75,  71,  68)
 #define png_cHRM PNG_U32( 99,  72,  82,  77)
+#define png_dSIG PNG_U32(100,  83,  73,  71) /* separate spec */
 #define png_fRAc PNG_U32(102,  82,  65,  99) /* registered, not defined */
 #define png_gAMA PNG_U32(103,  65,  77,  65)
 #define png_gIFg PNG_U32(103,  73,  70, 103)