diff --git a/ANNOUNCE b/ANNOUNCE
index 4d671833e..7db603526 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.6.0beta21 - March 29, 2012
+Libpng 1.6.0beta21 - April 13, 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.
@@ -349,7 +349,8 @@ Version 1.6.0beta20 [March 29, 2012]
   Revised png_set_text_2() to avoid potential memory corruption (fixes
     CVE-2011-3048).
 
-Version 1.6.0beta21 [March 29, 2012]
+Version 1.6.0beta21 [April 13, 2012]
+  Enable png_set_check_for_invalid_index() for both read and write.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
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diff --git a/CHANGES b/CHANGES
index 177b74390..b1fc74a5c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4100,7 +4100,8 @@ Version 1.6.0beta20 [March 29, 2012]
   Revised png_set_text_2() to avoid potential memory corruption (fixes
     CVE-2011-3048).
 
-Version 1.6.0beta21 [March 29, 2012]
+Version 1.6.0beta21 [April 13, 2012]
+  Enable png_set_check_for_invalid_index() for both read and write.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngset.c b/pngset.c
index fb950af21..7f159a042 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1369,7 +1369,7 @@ png_set_benign_errors(png_structrp png_ptr, int allowed)
 }
 #endif /* PNG_BENIGN_ERRORS_SUPPORTED */
 
-#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+#ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
    /* Do not report invalid palette index; added at libng-1.5.10 */
 void PNGAPI
 png_set_check_for_invalid_index(png_structrp png_ptr, int allowed)