diff --git a/egs/libriheavy/LM/zipformer1/subformer.py b/egs/libriheavy/LM/zipformer1/subformer.py
index 48e632457..9f340f8e7 100644
--- a/egs/libriheavy/LM/zipformer1/subformer.py
+++ b/egs/libriheavy/LM/zipformer1/subformer.py
@@ -169,7 +169,7 @@ class Subformer(EncoderInterface):
                           encoders[mid+i] ]
             encoder = DownsampledSubformerEncoder(
                 this_list,
-                input_num_channels=encoder_dim[max(0, mid-2)],
+                input_num_channels=encoder_dim[max(0, mid-i-1)],
                 downsample=2,
             )
 
@@ -954,6 +954,9 @@ class DownsampledSubformerEncoder(nn.Module):
         self.out_combiner = BypassModule(max(e.embed_dim() for e in encoders),
                                          straight_through_rate=0.0)
 
+    def embed_dim(self):  # return output embed_dim.
+        return self.encoders[-1].embed_dim()
+
     def forward(self,
                 src: Tensor,
                 pos_emb: Tensor,