diff --git a/ANNOUNCE b/ANNOUNCE
index 946b53f87..4a59d1e4e 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -27,6 +27,7 @@ Changes since the last public release (1.6.16):
 
 Version 1.6.17beta01 [December 23, 2014]
   Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
+  Corrected the width limit calculation in png_check_IHDR().
 
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diff --git a/CHANGES b/CHANGES
index f2ddc1a18..fb7ffd796 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5127,6 +5127,7 @@ Version 1.6.16 [December 22, 2014]
 
 Version 1.6.17beta01 [December 23, 2014]
   Removed duplicate PNG_SAFE_LIMITS_SUPPORTED handling from pngconf.h
+  Corrected the width limit calculation in png_check_IHDR().
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/png.c b/png.c
index e5f74ec89..791e9b6e3 100644
--- a/png.c
+++ b/png.c
@@ -769,13 +769,13 @@ png_get_copyright(png_const_structrp png_ptr)
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.6.17beta01 - December 22, 2014" PNG_STRING_NEWLINE \
+     "libpng version 1.6.17beta01 - December 23, 2014" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2014 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 "libpng version 1.6.17beta01 - December 22, 2014\
+      return "libpng version 1.6.17beta01 - December 23, 2014\
       Copyright (c) 1998-2014 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -2492,12 +2492,12 @@ png_check_IHDR(png_const_structrp png_ptr,
       error = 1;
    }
 
-   else if (png_gt(width,
-                   (PNG_SIZE_MAX >> 3) /* 8-byte RGBA pixels */
-                   - 48                /* big_row_buf hack */
-                   - 1                 /* filter byte */
-                   - 7*8               /* rounding width to multiple of 8 pix */
-                   - 8))               /* extra max_pixel_depth pad */
+   else if (png_gt(((width + 7) & (~7)),
+       ((PNG_SIZE_MAX
+           - 48        /* big_row_buf hack */
+           - 1)        /* filter byte */
+           / 8)        /* 8-byte RGBA pixels */
+           - 1))       /* extra max_pixel_depth pad */
    {
       /* The size of the row must be within the limits of this architecture.
        * Because the read code can perform arbitrary transformations the