diff --git a/ANNOUNCE b/ANNOUNCE
index 0b7d4c80..bc250363 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.2.57beta01 - June 4, 2016
+Libpng 1.2.57beta01 - December 27, 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.
@@ -40,7 +40,7 @@ Other information:
 
 Changes since the last public release (1.2.56):
 
-version 1.2.57beta01 [June 4, 2016]
+version 1.2.57beta01 [December 27, 2016]
   Fix typos in libpng.3 synopses (Eric S. Raymond).
   Fixed undefined behavior in png_push_save_buffer(). Do not call
     memcpy() with a null source, even if count is zero (Leon Scroggins III).
diff --git a/CHANGES b/CHANGES
index bcdd751b..feb2c548 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2920,7 +2920,7 @@ version 1.2.56rc01 [December 14, 2015]
 version 1.2.56 [December 17, 2015]
   No changes.
 
-version 1.2.57beta01 [June 4, 2016]
+version 1.2.57beta01 [December 27, 2016]
   Fix typos in libpng.3 synopses (Eric S. Raymond).
   Fixed undefined behavior in png_push_save_buffer(). Do not call
     memcpy() with a null source, even if count is zero (Leon Scroggins III).
diff --git a/png.c b/png.c
index 778952b2..f7425997 100644
--- a/png.c
+++ b/png.c
@@ -1,8 +1,8 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.2.54 [November 12, 2015]
- * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson
+ * Last changed in libpng 1.2.57 [%RDATE%]
+ * 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.)
  *
@@ -731,14 +731,14 @@ png_get_copyright(png_structp png_ptr)
 #else
 #ifdef __STDC__
    return ((png_charp) PNG_STRING_NEWLINE \
-     "libpng version 1.2.57beta01 - January 3, 2016" PNG_STRING_NEWLINE \
+     "libpng version 1.2.57beta01 - December 27, 2016" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2002,2004,2006-2016 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 1.2.57beta01 - January 3, 2016\
+   return ((png_charp) "libpng version 1.2.57beta01 - December 27, 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.");