diff --git a/ChangeLog b/ChangeLog
index 0c7f654e9e..b03275190e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Jun 20 16:36:14 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* missing/setproctitle.c (environ): use (*_NSGetEnviron()) instead of
+	  environ on Darwin for namespace cleanness, same as [ruby-core:00537].
+	  [ruby-core:45615] [Bug #6576]
+
 Wed Jun 20 11:33:04 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* process.c (rb_execarg_addopt): always make Fixnum, and ignore higher
diff --git a/missing/setproctitle.c b/missing/setproctitle.c
index 169ba8bcd2..d35e70d534 100644
--- a/missing/setproctitle.c
+++ b/missing/setproctitle.c
@@ -48,6 +48,12 @@
 #endif
 #include <string.h>
 
+#if defined(__APPLE__)
+#include <crt_externs.h>
+#undef environ
+#define environ (*_NSGetEnviron())
+#endif
+
 #define SPT_NONE	0	/* don't use it at all */
 #define SPT_PSTAT	1	/* use pstat(PSTAT_SETCMD, ...) */
 #define SPT_REUSEARGV	2	/* cover argv with title information */