diff --git a/ChangeLog b/ChangeLog
index 9b4c193671..5b8c4221fe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Nov 26 07:17:58 2009  wanabe  <s.wanabe@gmail.com>
+
+	* marshal.c (mark_dump_arg): mark str.  see also [ruby-dev:39735]
+
 Thu Nov 26 00:05:58 2009  NAKAMURA, Hiroshi  <nahi@ruby-lang.org>
 
 	* test/digest/test_digest_extend.rb: Added tests for current digest
diff --git a/marshal.c b/marshal.c
index 7acc495ca2..a0f9d76edb 100644
--- a/marshal.c
+++ b/marshal.c
@@ -166,6 +166,7 @@ mark_dump_arg(void *ptr)
         return;
     rb_mark_set(p->data);
     rb_mark_hash(p->compat_tbl);
+    rb_gc_mark(p->str);
 }
 
 static void