diff --git a/egs/libriheavy/LM/zipformer1/subformer.py b/egs/libriheavy/LM/zipformer1/subformer.py
index 15717a2b9..a87e0d8a9 100644
--- a/egs/libriheavy/LM/zipformer1/subformer.py
+++ b/egs/libriheavy/LM/zipformer1/subformer.py
@@ -677,7 +677,7 @@ class SubformerEncoder(nn.Module):
             assert seq_len % self.chunk_size == 0, (seq_len, self.chunk_size)
             num_layers = len(self.layers)
             chunk_indexes = [0, 1] * (num_layers + 1 // 2)
-            return [ self.chunk_size, self.chunk_size * 2 ], chunk_indexes[:num_layers]
+            return [ self.chunk_size, seq_len ], chunk_indexes[:num_layers]
 
 
     def _to_chunk_size(self, src: Tensor, chunk_size: int) -> Tensor:
diff --git a/egs/libriheavy/LM/zipformer1/train.py b/egs/libriheavy/LM/zipformer1/train.py
index 0d4f48b89..278c5bdd6 100755
--- a/egs/libriheavy/LM/zipformer1/train.py
+++ b/egs/libriheavy/LM/zipformer1/train.py
@@ -395,7 +395,7 @@ def get_params() -> AttributeDict:
             "warm_step": 2000,
             "env_info": get_env_info(),
             "bytes_per_segment": 2048,
-            "batch_size": 22,
+            "batch_size": 20,
             "train_file_list": "train.txt",
             "valid_file_list": "valid.txt",
             "num_workers": 4,