diff --git a/ANNOUNCE b/ANNOUNCE
index 3d6ffad3..50ce29e1 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.2.43beta01 - January 4, 2010
+Libpng 1.2.43beta01 - January 14, 2010
 
 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.
@@ -42,9 +42,13 @@ Other information:
 
 Changes since the last public release (1.2.42):
 
-version 1.2.43beta01 [January 4, 2010]
+version 1.2.43beta01 [January 14, 2010]
   Updated CMakeLists.txt for consistent indentation and to avoid an
     unclosed if-statement warning (Philip Lowman).
+  Removed "#ifdef PNG_1_0_X / #endif" surrounding
+    PNG_READ_16_TO_8_SUPPORTED and PNG_READ_GRAY_TO_RGB_SUPPORTED
+    in pngconf.h.  These were added in libpng-1.2.41beta08 and libpng-1.0.51,
+    which introduced a binary incompatibility with libpng-1.0.50.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 
diff --git a/CHANGES b/CHANGES
index 6520d861..244688f8 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2643,9 +2643,13 @@ version 1.2.42rc05 [January 2, 2010]
 version 1.2.42 and 1.0.52 [January 3, 2010]
   No changes.
 
-version 1.2.43beta01 [January 4, 2010]
+version 1.2.43beta01 [January 14, 2010]
   Updated CMakeLists.txt for consistent indentation and to avoid an
     unclosed if-statement warning (Philip Lowman).
+  Removed "#ifdef PNG_1_0_X / #endif" surrounding
+    PNG_READ_16_TO_8_SUPPORTED and PNG_READ_GRAY_TO_RGB_SUPPORTED
+    in pngconf.h.  These were added in libpng-1.2.41beta08 and libpng-1.0.51,
+    which introduced a binary incompatibility with libpng-1.0.50.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
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diff --git a/pngconf.h b/pngconf.h
index 00abdba4..1c5b2044 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.2.43beta01 - January 3, 2010
+ * libpng version 1.2.43beta01 - January 14, 2010
  * Copyright (c) 1998-2010 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.)
@@ -622,22 +622,18 @@
 #  ifndef PNG_NO_READ_BACKGROUND
 #    define PNG_READ_BACKGROUND_SUPPORTED
 #  endif
-#ifndef PNG_1_0_X
 #  ifndef PNG_NO_READ_16_TO_8
 #    define PNG_READ_16_TO_8_SUPPORTED
 #  endif
-#endif
 #  ifndef PNG_NO_READ_FILLER
 #    define PNG_READ_FILLER_SUPPORTED
 #  endif
 #  ifndef PNG_NO_READ_GAMMA
 #    define PNG_READ_GAMMA_SUPPORTED
 #  endif
-#ifndef PNG_1_0_X
 #  ifndef PNG_NO_READ_GRAY_TO_RGB
 #    define PNG_READ_GRAY_TO_RGB_SUPPORTED
 #  endif
-#endif
 #  ifndef PNG_NO_READ_SWAP_ALPHA
 #    define PNG_READ_SWAP_ALPHA_SUPPORTED
 #  endif