diff --git a/ChangeLog b/ChangeLog
index f780c1190f..3a732b4cb7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Nov 30 23:48:07 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* signal.c (ruby_signal): use SA_SIGINFO if available.
+	  [ ruby-Patches-6418 ]
+
 Fri Nov 30 22:52:54 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* signal.c (trap_signm): SIGVTALRM no longer used for green
diff --git a/include/ruby/intern.h b/include/ruby/intern.h
index b8c43b2717..a43d4d31ab 100644
--- a/include/ruby/intern.h
+++ b/include/ruby/intern.h
@@ -472,7 +472,7 @@ VALUE rb_f_kill(int, VALUE*);
 void rb_gc_mark_trap_list(void);
 #ifdef POSIX_SIGNAL
 #define posix_signal ruby_posix_signal
-void posix_signal(int, RETSIGTYPE (*)(int));
+RETSIGTYPE (*posix_signal(int, RETSIGTYPE (*)(int)))(int);
 #endif
 void ruby_sig_finalize(void);
 void rb_trap_exit(void);
diff --git a/process.c b/process.c
index 13f4bef765..525a546d6e 100644
--- a/process.c
+++ b/process.c
@@ -1668,6 +1668,10 @@ rb_f_abort(int argc, VALUE *argv)
 
 #if defined(sun)
 #define signal(a,b) sigset(a,b)
+#else
+# if defined(POSIX_SIGNAL)
+#  define signal(a,b) posix_signal(a,b)
+# endif
 #endif
 
 void
diff --git a/signal.c b/signal.c
index 6eba832e5d..5723d7f031 100644
--- a/signal.c
+++ b/signal.c
@@ -414,9 +414,15 @@ ruby_signal(int signum, sighandler_t handler)
 
     rb_trap_accept_nativethreads[signum] = 0;
 
-    sigact.sa_handler = handler;
     sigemptyset(&sigact.sa_mask);
+#ifdef SA_SIGINFO
+    sigact.sa_sigaction = (void (*)(int, siginfo_t*, void*))handler;
+    sigact.sa_flags = SA_SIGINFO;
+#else
+    sigact.sa_handler = handler;
     sigact.sa_flags = 0;
+#endif
+
 #ifdef SA_NOCLDWAIT
     if (signum == SIGCHLD && handler == SIG_IGN)
 	sigact.sa_flags |= SA_NOCLDWAIT;
@@ -425,7 +431,7 @@ ruby_signal(int signum, sighandler_t handler)
     return old.sa_handler;
 }
 
-void
+sighandler_t
 posix_signal(int signum, sighandler_t handler)
 {
     ruby_signal(signum, handler);