diff --git a/paddlespeech/s2t/modules/decoder_layer.py b/paddlespeech/s2t/modules/decoder_layer.py
index 37b124e84..cb7261107 100644
--- a/paddlespeech/s2t/modules/decoder_layer.py
+++ b/paddlespeech/s2t/modules/decoder_layer.py
@@ -114,10 +114,7 @@ class DecoderLayer(nn.Layer):
             ], f"{cache.shape} == {[tgt.shape[0], tgt.shape[1] - 1, self.size]}"
             tgt_q = tgt[:, -1:, :]
             residual = residual[:, -1:, :]
-            # TODO(Hui Zhang): slice not support bool type
-            # tgt_q_mask = tgt_mask[:, -1:, :]
-            tgt_q_mask = tgt_mask.cast(paddle.int64)[:, -1:, :].cast(
-                paddle.bool)
+            tgt_q_mask = tgt_mask[:, -1:, :]
 
         if self.concat_after:
             tgt_concat = paddle.cat(