diff --git a/TensorFlow2/built-in/nlp/BERT_ID2478_for_TensorFlow2.X/npu_ops.py b/TensorFlow2/built-in/nlp/BERT_ID2478_for_TensorFlow2.X/npu_ops.py
index 43406a1b3aa32852e6438d646b9568876d540068..fa6f8f211c19e1bce9d78a90c7c11b6121efdbd7 100644
--- a/TensorFlow2/built-in/nlp/BERT_ID2478_for_TensorFlow2.X/npu_ops.py
+++ b/TensorFlow2/built-in/nlp/BERT_ID2478_for_TensorFlow2.X/npu_ops.py
@@ -145,7 +145,7 @@ def dropout(x, keep_prob, noise_shape=None, seed=None, name=None):
     result = gen_npu_ops.drop_out_do_mask(x, gen_out, keep_prob, name)
     return result
 
-# @ops.RegisterGradient("DropOutDoMask")
+@ops.RegisterGradient("DropOutDoMask")
 def _DropOutDoMaskGrad(op, grad):
     result = gen_npu_ops.drop_out_do_mask(grad, op.inputs[1],  op.inputs[2])
     return [result, None, None]