diff --git a/ANNOUNCE b/ANNOUNCE
index 765f99f8f..fd8c00523 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.5.10beta04 - March 9, 2012
+Libpng 1.5.10beta04 - March 10, 2012
 
 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.
@@ -50,11 +50,10 @@ Version 1.5.10beta03 [March 6, 2012]
     of png_ptr->current_text from pngread.c
   Added palette-index checking.
 
-Version 1.5.10beta04 [March 9, 2012]
+Version 1.5.10beta04 [March 10, 2012]
   Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition.
-  Disabled part of the CMF optimization of non-IDAT compressed chunks, which
-    was added at libpng-1.5.4.  It sometimes produces too small of a window.
-    This has been fixed in libpng-1.6.0.
+  Fixed CMF optimization of non-IDAT compressed chunks, which was added at
+    libpng-1.5.4.  It sometimes produces too small of a window.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 0e48894a6..e99ac82db 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3835,11 +3835,10 @@ Version 1.5.10beta03 [March 6, 2012]
     of png_ptr->current_text from pngread.c
   Added palette-index checking.
 
-Version 1.5.10beta04 [March 9, 2012]
+Version 1.5.10beta04 [March 10, 2012]
   Fixed PNG_LIBPNG_BUILD_BASE_TYPE definition.
-  Disabled part of the CMF optimization of non-IDAT compressed chunks, which
-    was added at libpng-1.5.4.  It sometimes produces too small of a window.
-    This has been fixed in libpng-1.6.0.
+  Fixed CMF optimization of non-IDAT compressed chunks, which was added at
+    libpng-1.5.4.  It sometimes produces too small of a window.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngwutil.c b/pngwutil.c
index d8c00dc15..366d98a9e 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -569,14 +569,15 @@ png_text_compress(png_structp png_ptr,
 
 /* Ship the compressed text out via chunk writes */
 static void /* PRIVATE */
-png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
+png_write_compressed_data_out(png_structp png_ptr, compression_state *comp,
+   png_size_t data_len)
 {
    int i;
 
    /* Handle the no-compression case */
    if (comp->input)
    {
-      png_write_chunk_data(png_ptr, comp->input, comp->input_len);
+      png_write_chunk_data(png_ptr, comp->input, data_len);
 
       return;
    }
@@ -585,7 +586,7 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
    /* The zbuf_size test is because the code below doesn't work if zbuf_size is
     * '1'; simply skip it to avoid memory overwrite.
     */
-   if (comp->input_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1)
+   if (data_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1)
    {
       unsigned int z_cmf;  /* zlib compression method and flags */
 
@@ -619,7 +620,6 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
          if (comp->num_output_ptr)
          {
 
-#if 0 /* The following sometimes produces incorrect zlib datastreams */
            if (comp->output_ptr[0][0] != z_cmf)
            {
               int tmp;
@@ -629,7 +629,6 @@ png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
               tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
               comp->output_ptr[0][1] = (png_byte)tmp;
            }
-#endif /* 0 */
          }
          else
          {
@@ -1166,8 +1165,7 @@ png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type,
 
    if (profile_len)
    {
-      comp.input_len = profile_len;
-      png_write_compressed_data_out(png_ptr, &comp);
+      png_write_compressed_data_out(png_ptr, &comp, profile_len);
    }
 
    png_write_chunk_end(png_ptr);
@@ -1737,8 +1735,7 @@ png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text,
    png_write_chunk_data(png_ptr, &buf, (png_size_t)1);
 
    /* Write the compressed data */
-   comp.input_len = text_len;
-   png_write_compressed_data_out(png_ptr, &comp);
+   png_write_compressed_data_out(png_ptr, &comp, text_len);
 
    /* Close the chunk */
    png_write_chunk_end(png_ptr);
@@ -1829,7 +1826,7 @@ png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key,
    png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf),
        (png_size_t)(lang_key_len + 1));
 
-   png_write_compressed_data_out(png_ptr, &comp);
+   png_write_compressed_data_out(png_ptr, &comp, text_len);
 
    png_write_chunk_end(png_ptr);