diff --git a/ANNOUNCE b/ANNOUNCE
index 6723c9f99..9be49af9f 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.5.1rc02 - January 29, 2011
+Libpng 1.5.1rc02 - January 30, 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.
@@ -115,13 +115,13 @@ Version 1.5.1beta11 [January 28, 2011]
     architectures.
   Added transform tests to pngvalid and simplified the arguments.
 
-Version 1.5.1rc01 [January 29, 2011]
+Version 1.5.1rc01 [January 30, 2011]
   No changes.
 
-Version 1.5.1rc02 [January 29, 2011]
+Version 1.5.1rc02 [January 30, 2011]
   Added a request in the manual that applications do not use "png_" or
     "PNG_" to begin any of their own symbols.
-
+  Changed PNG_UNUSED to "(void)param;"
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index ec7bab2b6..10e99ac8f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3231,12 +3231,13 @@ Version 1.5.1beta11 [January 28, 2011]
     architectures.
   Added transform tests to pngvalid and simplified the arguments.
 
-Version 1.5.1rc01 [January 29, 2011]
+Version 1.5.1rc01 [January 30, 2011]
   No changes.
 
-Version 1.5.1rc02 [January 29, 2011]
+Version 1.5.1rc02 [January 30, 2011]
   Added a request in the manual that applications do not use "png_" or
     "PNG_" to begin any of their own symbols.
+  Changed PNG_UNUSED to "(void)param;"
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngpriv.h b/pngpriv.h
index 70eac1f53..d3903a960 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -89,7 +89,7 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
  * the terminating semicolon.  Also note that some of these might not
  * work when "param" is a structure, but that is never the case in libpng.
  */
-#define PNG_UNUSED(param) {if(param){}}
+#define PNG_UNUSED(param) (void)param;
 
 #if 0 /* Possibilities discussed on png-mng-implement, starting 27 Jan 2011 */
 #ifndef PNG_UNUSED                                 /* "best" but complex */
@@ -98,6 +98,7 @@ typedef PNG_CONST png_uint_16p FAR * png_const_uint_16pp;
  #else
  #  define PNG_UNUSED(param)
  #endif
+#define PNG_UNUSED(param) {if(param){}}
 #define PNG_UNUSED(param) param = param;            /* What we used before */
 #define PNG_UNUSED(param) {(void)param;}            /* Visual C complains */
 #define PNG_UNUSED(param) if(param);                /* gcc-4.2 complains */