1 files changed, 2 insertions, 2 deletions
diff --git a/thread.c b/thread.c
index bd8fcfb124..47ed9e0ed2 100644
--- a/thread.c
+++ b/thread.c
@@ -478,9 +478,9 @@ thread_start_func_2(rb_thread_t *th, VALUE *stack_start, VALUE *register_stack_s
 		    th->errinfo = Qnil;
 		    th->root_lep = rb_vm_ep_local_ep(proc->block.ep);
 		    th->root_svar = Qnil;
-		    EXEC_EVENT_HOOK(th, RUBY_EVENT_THREAD_BEGIN, proc->block.self, 0, 0, th->self);
+		    EXEC_EVENT_HOOK(th, RUBY_EVENT_THREAD_BEGIN, th->self, 0, 0, Qundef);
 		    th->value = rb_vm_invoke_proc(th, proc, (int)RARRAY_LEN(args), RARRAY_PTR(args), 0);
-		    EXEC_EVENT_HOOK(th, RUBY_EVENT_THREAD_END, proc->block.self, 0, 0, th->self);
+		    EXEC_EVENT_HOOK(th, RUBY_EVENT_THREAD_END, th->self, 0, 0, Qundef);
 		}
 		else {
 		    th->value = (*th->first_func)((void *)args);