diff --git a/ANNOUNCE b/ANNOUNCE
index f82cb503..6b7168cb 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.2.40beta01 - August 13, 2009
+Libpng 1.2.40beta01 - August 20, 2009
 
 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.
@@ -42,8 +42,9 @@ Other information:
 
 Changes since the last public release (1.2.39):
 
-version 1.2.40beta01 [August 13, 2009]
+version 1.2.40beta01 [August 20, 2009]
   Removed an extra png_debug() recently added to png_write_find_filter().
+  Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 
diff --git a/CHANGES b/CHANGES
index 594828d0..0de1b505 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2459,8 +2459,9 @@ version 1.2.39c01 [August 6, 2009]
 version 1.2.39 and 1.0.48 [August 13, 2009]
   No changes.
 
-version 1.2.40beta01 [August 13, 2009]
+version 1.2.40beta01 [August 20, 2009]
   Removed an extra png_debug() recently added to png_write_find_filter().
+  Fixed incorrect #ifdef in pngset.c regarding unknown chunk support.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngset.c b/pngset.c
index 3c110eba..91d2502c 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1,7 +1,7 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.2.39 [August 13, 2009]
+ * Last changed in libpng 1.2.40 [August 20, 2009]
  * Copyright (c) 1998-2009 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.)
@@ -25,6 +25,7 @@ void PNGAPI
 png_set_bKGD(png_structp png_ptr, png_infop info_ptr, png_color_16p background)
 {
    png_debug1(1, "in %s storage function", "bKGD");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -41,6 +42,7 @@ png_set_cHRM(png_structp png_ptr, png_infop info_ptr,
    double green_x, double green_y, double blue_x, double blue_y)
 {
    png_debug1(1, "in %s storage function", "cHRM");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -74,6 +76,7 @@ png_set_cHRM_fixed(png_structp png_ptr, png_infop info_ptr,
    png_fixed_point blue_x, png_fixed_point blue_y)
 {
    png_debug1(1, "in %s storage function", "cHRM fixed");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -112,7 +115,9 @@ void PNGAPI
 png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma)
 {
    double png_gamma;
+
    png_debug1(1, "in %s storage function", "gAMA");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -140,6 +145,7 @@ png_set_gAMA_fixed(png_structp png_ptr, png_infop info_ptr, png_fixed_point
    png_fixed_point png_gamma;
 
    png_debug1(1, "in %s storage function", "gAMA");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -177,8 +183,10 @@ png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p hist)
    int i;
 
    png_debug1(1, "in %s storage function", "hIST");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
+
    if (info_ptr->num_palette == 0 || info_ptr->num_palette
        > PNG_MAX_PALETTE_LENGTH)
    {
@@ -221,6 +229,7 @@ png_set_IHDR(png_structp png_ptr, png_infop info_ptr,
    int filter_type)
 {
    png_debug1(1, "in %s storage function", "IHDR");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -328,6 +337,7 @@ png_set_oFFs(png_structp png_ptr, png_infop info_ptr,
    png_int_32 offset_x, png_int_32 offset_y, int unit_type)
 {
    png_debug1(1, "in %s storage function", "oFFs");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -348,6 +358,7 @@ png_set_pCAL(png_structp png_ptr, png_infop info_ptr,
    int i;
 
    png_debug1(1, "in %s storage function", "pCAL");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -417,6 +428,7 @@ png_set_sCAL(png_structp png_ptr, png_infop info_ptr,
              int unit, double width, double height)
 {
    png_debug1(1, "in %s storage function", "sCAL");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -435,6 +447,7 @@ png_set_sCAL_s(png_structp png_ptr, png_infop info_ptr,
    png_uint_32 length;
 
    png_debug1(1, "in %s storage function", "sCAL");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -480,6 +493,7 @@ png_set_pHYs(png_structp png_ptr, png_infop info_ptr,
    png_uint_32 res_x, png_uint_32 res_y, int unit_type)
 {
    png_debug1(1, "in %s storage function", "pHYs");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -496,6 +510,7 @@ png_set_PLTE(png_structp png_ptr, png_infop info_ptr,
 {
 
    png_debug1(1, "in %s storage function", "PLTE");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -546,6 +561,7 @@ png_set_sBIT(png_structp png_ptr, png_infop info_ptr,
    png_color_8p sig_bit)
 {
    png_debug1(1, "in %s storage function", "sBIT");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -559,6 +575,7 @@ void PNGAPI
 png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int intent)
 {
    png_debug1(1, "in %s storage function", "sRGB");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -586,6 +603,7 @@ png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr,
       int_green_y, int_blue_x, int_blue_y;
 #endif
    png_debug1(1, "in %s storage function", "sRGB_gAMA_and_cHRM");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -655,6 +673,7 @@ png_set_iCCP(png_structp png_ptr, png_infop info_ptr,
    png_uint_32 length;
 
    png_debug1(1, "in %s storage function", "iCCP");
+
    if (png_ptr == NULL || info_ptr == NULL || name == NULL || profile == NULL)
       return;
 
@@ -869,6 +888,7 @@ void PNGAPI
 png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_timep mod_time)
 {
    png_debug1(1, "in %s storage function", "tIME");
+
    if (png_ptr == NULL || info_ptr == NULL ||
        (png_ptr->mode & PNG_WROTE_tIME))
       return;
@@ -884,6 +904,7 @@ png_set_tRNS(png_structp png_ptr, png_infop info_ptr,
    png_bytep trans, int num_trans, png_color_16p trans_values)
 {
    png_debug1(1, "in %s storage function", "tRNS");
+
    if (png_ptr == NULL || info_ptr == NULL)
       return;
 
@@ -1008,7 +1029,7 @@ png_set_sPLT(png_structp png_ptr,
 }
 #endif /* PNG_sPLT_SUPPORTED */
 
-#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
 void PNGAPI
 png_set_unknown_chunks(png_structp png_ptr,
    png_infop info_ptr, png_unknown_chunkp unknowns, int num_unknowns)
@@ -1088,7 +1109,9 @@ png_permit_empty_plte (png_structp png_ptr, int empty_plte_permitted)
 {
    /* This function is deprecated in favor of png_permit_mng_features()
       and will be removed from libpng-1.3.0 */
+
    png_debug(1, "in png_permit_empty_plte, DEPRECATED.");
+
    if (png_ptr == NULL)
       return;
    png_ptr->mng_features_permitted = (png_byte)
@@ -1103,6 +1126,7 @@ png_uint_32 PNGAPI
 png_permit_mng_features (png_structp png_ptr, png_uint_32 mng_features)
 {
    png_debug(1, "in png_permit_mng_features");
+
    if (png_ptr == NULL)
       return (png_uint_32)0;
    png_ptr->mng_features_permitted =
@@ -1164,8 +1188,10 @@ png_set_read_user_chunk_fn(png_structp png_ptr, png_voidp user_chunk_ptr,
    png_user_chunk_ptr read_user_chunk_fn)
 {
    png_debug(1, "in png_set_read_user_chunk_fn");
+
    if (png_ptr == NULL)
       return;
+
    png_ptr->read_user_chunk_fn = read_user_chunk_fn;
    png_ptr->user_chunk_ptr = user_chunk_ptr;
 }