diff --git a/ChangeLog b/ChangeLog
index c9d3d72aa8..41bd1379f7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Mar 10 15:02:39 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* process.c (setup_communication_pipe): remove unused function.
+	  it was unintentionally added r39683.
+
 Wed Mar  6 00:30:40 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* tool/gen_ruby_tapset.rb: add tapset generator.
diff --git a/process.c b/process.c
index 92966f1bb2..f5ccbbe1d2 100644
--- a/process.c
+++ b/process.c
@@ -1079,32 +1079,6 @@ before_exec_non_async_signal_safe(void)
     }
 }
 
-static void
-setup_communication_pipe(void)
-{
-#if USE_SLEEPY_TIMER_THREAD
-	/* communication pipe with timer thread and signal handler */
-	if (timer_thread_pipe_owner_process != getpid()) {
-	    if (timer_thread_pipe[0] != -1) {
-		/* close pipe of parent process */
-		close_communication_pipe();
-	    }
-
-	    err = rb_cloexec_pipe(timer_thread_pipe);
-	    if (err != 0) {
-		rb_bug_errno("thread_timer: Failed to create communication pipe for timer thread", errno);
-	    }
-            rb_update_max_fd(timer_thread_pipe[0]);
-            rb_update_max_fd(timer_thread_pipe[1]);
-	    set_nonblock(timer_thread_pipe[0]);
-	    set_nonblock(timer_thread_pipe[1]);
-
-	    /* validate pipe on this process */
-	    timer_thread_pipe_owner_process = getpid();
-	}
-#endif /* USE_SLEEPY_TIMER_THREAD */
-}
-
 static void
 before_exec(void)
 {