diff --git a/codes/models/audio/tts/transformer_builders.py b/codes/models/audio/tts/transformer_builders.py
index 8ce96f38..06f4a44d 100644
--- a/codes/models/audio/tts/transformer_builders.py
+++ b/codes/models/audio/tts/transformer_builders.py
@@ -59,8 +59,8 @@ def build_hf_gpt_transformer(layers, model_dim, heads, max_mel_seq_len, max_text
     """
     from transformers import GPT2Config, GPT2Model
     gpt_config = GPT2Config(vocab_size=256,  # Unused.
-                             n_positions=1,
-                             n_ctx=1,
+                             n_positions=max_mel_seq_len+max_text_seq_len,
+                             n_ctx=max_mel_seq_len+max_text_seq_len,
                              n_embd=model_dim,
                              n_layer=layers,
                              n_head=heads,