diff --git a/ChangeLog b/ChangeLog
index a2ed0724fa..171ecaf450 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Fri Dec 14 10:36:10 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* vm_trace.c (exec_hooks): add volatile to avoid segv.
+	  On test-all with -j, it may crash in TH_POP_TAG.
+	  Detailed mechanism is not known but this fixes it.
+
 Fri Dec 14 04:08:05 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* test/ruby/envutil.rb (EnvUtil::Unit::Assertionsassert_separately):
diff --git a/vm_trace.c b/vm_trace.c
index 717723c635..f5260149b3 100644
--- a/vm_trace.c
+++ b/vm_trace.c
@@ -244,7 +244,7 @@ clean_hooks(rb_hook_list_t *list)
 static int
 exec_hooks(rb_thread_t *th, rb_hook_list_t *list, const rb_trace_arg_t *trace_arg, int can_clean_hooks)
 {
-    int state;
+    volatile int state;
     volatile int raised;
 
     if (UNLIKELY(list->need_clean > 0) && can_clean_hooks) {
@@ -275,6 +275,9 @@ exec_hooks(rb_thread_t *th, rb_hook_list_t *list, const rb_trace_arg_t *trace_ar
     if (raised) {
 	rb_threadptr_set_raised(th);
     }
+    {
+	rb_thread_t volatile *tmp = th;
+    }
 
     return state;
 }