diff --git a/ChangeLog b/ChangeLog
index 1ee37b3047..52cc578989 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Oct  6 01:44:51 2011  CHIKANAGA Tomoyuki  <nagachika00@gmail.com>
+
+	* cont.c (cont_mark): mark original Thread object from saved_thread.
+	  [ruby-dev:44567] [Bug #5386]
+
 Wed Oct  5 16:33:04 2011  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* vm_insnhelper.c (vm_call_cfunc): remove useless hack.
diff --git a/cont.c b/cont.c
index 3e68d897ca..22944d6dee 100644
--- a/cont.c
+++ b/cont.c
@@ -139,6 +139,7 @@ cont_mark(void *ptr)
 	rb_context_t *cont = ptr;
 	rb_gc_mark(cont->value);
 	rb_thread_mark(&cont->saved_thread);
+	rb_gc_mark(cont->saved_thread.self);
 
 	if (cont->vm_stack) {
 #ifdef CAPTURE_JUST_VALID_VM_STACK