1 files changed, 0 insertions, 1 deletions
diff --git a/thread.c b/thread.c
index 13c8942368..e4506c2374 100644
--- a/thread.c
+++ b/thread.c
@@ -5126,7 +5126,6 @@ Init_Thread(void)
 	    th->async_errinfo_queue = rb_ary_tmp_new(0);
 	    th->async_errinfo_queue_checked = 0;
 	    th->async_errinfo_mask_stack = rb_ary_tmp_new(0);
-	    RBASIC(th->async_errinfo_mask_stack)->klass = 0;
 	}
     }