diff --git a/ChangeLog b/ChangeLog
index 2a14677b7a..05e8519826 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Jan 17 17:13:46 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* missing/setproctitle.c (ruby_init_setproctitle): changed prefix.
+
 Tue Jan 17 12:32:46 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* gc.c (aligned_malloc, aligned_free): covered missing defined
diff --git a/missing/setproctitle.c b/missing/setproctitle.c
index f4078bd993..169ba8bcd2 100644
--- a/missing/setproctitle.c
+++ b/missing/setproctitle.c
@@ -34,6 +34,7 @@
 
 #include "ruby.h"
 #include "ruby/util.h"
+#define compat_init_setproctitle ruby_init_setproctitle
 
 #ifndef HAVE_SETPROCTITLE
 
diff --git a/ruby.c b/ruby.c
index 7e06a128dc..1ad68caeb1 100644
--- a/ruby.c
+++ b/ruby.c
@@ -1809,8 +1809,8 @@ ruby_process_options(int argc, char **argv)
 
 #ifndef HAVE_SETPROCTITLE
     {
-	extern void compat_init_setproctitle(int argc, char *argv[]);
-	compat_init_setproctitle(argc, argv);
+	extern void ruby_init_setproctitle(int argc, char *argv[]);
+	ruby_init_setproctitle(argc, argv);
     }
 #endif