diff --git a/egs/librispeech/ASR/zipformer/decode_stream.py b/egs/librispeech/ASR/zipformer/decode_stream.py
index 0f66ad59c7..d6918bf328 100644
--- a/egs/librispeech/ASR/zipformer/decode_stream.py
+++ b/egs/librispeech/ASR/zipformer/decode_stream.py
@@ -84,7 +84,7 @@ def __init__(
             self.hyps = HypothesisList()
             self.hyps.add(
                 Hypothesis(
-                    ys=[params.blank_id] * params.context_size,
+                    ys=[-1] * (params.context_size - 1) + [params.blank_id],
                     log_prob=torch.zeros(1, dtype=torch.float32, device=device),
                 )
             )