diff --git a/paddlespeech/t2s/modules/nets_utils.py b/paddlespeech/t2s/modules/nets_utils.py
index 0238f4db..8cf17a6a 100644
--- a/paddlespeech/t2s/modules/nets_utils.py
+++ b/paddlespeech/t2s/modules/nets_utils.py
@@ -147,7 +147,7 @@ def make_pad_mask(lengths, xs=None, length_dim=-1):
     seq_range = paddle.arange(0, maxlen, dtype=paddle.int64)
     seq_range_expand = seq_range.unsqueeze(0).expand([bs, maxlen])
     seq_length_expand = lengths.unsqueeze(-1)
-    mask = seq_range_expand >= seq_length_expand
+    mask = seq_range_expand >= seq_length_expand.cast(seq_range_expand.dtype)
 
     if xs is not None:
         assert paddle.shape(xs)[0] == bs, (paddle.shape(xs)[0], bs)