diff --git a/ChangeLog b/ChangeLog
index f9b82342c5..688e77c209 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Apr 30 00:16:40 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* thread_pthread.c (gvl_init): fix hangup if GVL_SIMPLE_LOCK=1.
+	  We don't have to call mutex_unlock() before initialize it!
+
 Fri Apr 29 13:15:15 2011  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* thread_win32.c (native_cond_timedwait): New. r31373 caused
diff --git a/thread_pthread.c b/thread_pthread.c
index f60da8ab7e..4161f663db 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -128,7 +128,7 @@ gvl_init(rb_vm_t *vm)
     if (GVL_DEBUG) fprintf(stderr, "gvl init\n");
 
 #if GVL_SIMPLE_LOCK
-    native_mutex_reinitialize_atfork(&vm->gvl.lock);
+    native_mutex_initialize(&vm->gvl.lock);
 #else
     native_mutex_initialize(&vm->gvl.lock);
     vm->gvl.waiting_threads = 0;