diff --git a/ANNOUNCE b/ANNOUNCE
index 783834674..fe4e8b60d 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.4.8rc01 - June 4, 2011
+Libpng 1.4.8beta02 - June 5, 2011
 
 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.
@@ -9,20 +9,20 @@ Files available for download:
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   1.4.8rc01.tar.xz (LZMA-compressed, recommended)
-   1.4.8rc01.tar.gz
-   1.4.8rc01.tar.bz2
+   1.4.8beta02.tar.xz (LZMA-compressed, recommended)
+   1.4.8beta02.tar.gz
+   1.4.8beta02.tar.bz2
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lp148r01.7z (LZMA-compressed, recommended)
-   lp148r01.zip
+   lp148b02.7z (LZMA-compressed, recommended)
+   lp148b02.zip
 
 Other information:
 
-   1.4.8rc01-README.txt
-   1.4.8rc01-LICENSE.txt
+   1.4.8beta02-README.txt
+   1.4.8beta02-LICENSE.txt
 
 Changes since the last public release (1.4.7):
 
@@ -34,10 +34,12 @@ version 1.4.8beta01 [June 4, 2011]
     was introduced in libpng-1.2.20beta01.
   Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
     before IDAT.
-  Port change to pngrtran.c from 1.5.3: when expanding a paletted image,
+  Ported bugfix in pngrtran.c from 1.5.3: when expanding a paletted image,
     always expand to RGBA if transparency is present.
 
-version 1.4.8beta02 [June 4, 2011]
+version 1.4.8beta02 [June 5, 2011]
+  Ported bugfix in pngrtran.c from 1.5.3: Ensure coefficients are OK for
+    png_rgb_to_gray_fixed().
 
 Send comments/corrections/commendations to glennrp at users.sourceforge.net
 or to png-mng-implement at lists.sf.net (subscription required; visit
diff --git a/CHANGES b/CHANGES
index b9e550c54..dbbe871ce 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2802,10 +2802,12 @@ version 1.4.8beta01 [June 4, 2011]
     was introduced in libpng-1.2.20beta01.
   Check for up->location !PNG_AFTER_IDAT when writing unknown chunks
     before IDAT.
-  Port change to pngrtran.c from 1.5.3: when expanding a paletted image,
+  Ported bugfix in pngrtran.c from 1.5.3: when expanding a paletted image,
     always expand to RGBA if transparency is present.
 
-version 1.4.8beta02 [June 4, 2011]
+version 1.4.8beta02 [June 5, 2011]
+  Ported bugfix in pngrtran.c from 1.5.3: Ensure coefficients are OK for
+    png_rgb_to_gray_fixed().
 
 Send comments/corrections/commendations to glennrp at users.sourceforge.net
 or to png-mng-implement at lists.sf.net (subscription required; visit
diff --git a/pngrtran.c b/pngrtran.c
index 4cd4d8713..0a01db8ba 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -703,27 +703,38 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
    }
 #endif
    {
-      png_uint_16 red_int, green_int;
-      if (red < 0 || green < 0)
-      {
-         red_int   =  6968; /* .212671 * 32768 + .5 */
-         green_int = 23434; /* .715160 * 32768 + .5 */
-      }
-      else if (red + green < 100000L)
+      if (red >= 0 && green >= 0 && red + green <= 100000L)
       {
+         png_uint_16 red_int, green_int;
+
          red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
          green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
+
+         png_ptr->rgb_to_gray_red_coeff   = red_int;
+         png_ptr->rgb_to_gray_green_coeff = green_int;
+         png_ptr->rgb_to_gray_blue_coeff  =
+          (png_uint_16)(32768 - red_int - green_int);
       }
+
       else
       {
-         png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
-         red_int   =  6968;
-         green_int = 23434;
+         if (red >= 0 && green >= 0)
+            png_warning(png_ptr,
+               "ignoring out of range rgb_to_gray coefficients");
+
+         /* Use the defaults, from the cHRM chunk if set, else the built in Rec
+          * 709 values (which correspond to sRGB, so we don't have to worry
+          * about the sRGB chunk!)
+          */
+         if (png_ptr->rgb_to_gray_red_coeff == 0 &&
+            png_ptr->rgb_to_gray_green_coeff == 0 &&
+            png_ptr->rgb_to_gray_blue_coeff == 0)
+         {
+            png_ptr->rgb_to_gray_red_coeff   = 6968;  /* .212671 * 32768 + .5 */
+            png_ptr->rgb_to_gray_green_coeff = 23434; /* .715160 * 32768 + .5 */
+            png_ptr->rgb_to_gray_blue_coeff  = 2366;
+         }
       }
-      png_ptr->rgb_to_gray_red_coeff   = red_int;
-      png_ptr->rgb_to_gray_green_coeff = green_int;
-      png_ptr->rgb_to_gray_blue_coeff  =
-         (png_uint_16)(32768 - red_int - green_int);
    }
 }
 #endif