diff --git a/utils/synthesis.py b/utils/synthesis.py
index fce44dfe..6ae056b5 100644
--- a/utils/synthesis.py
+++ b/utils/synthesis.py
@@ -93,6 +93,7 @@ def synthesis(model,
             trim_silence (bool): trim silence after synthesis.
     """
     # GST processing
+    style_mel = None
     if CONFIG.model == "TacotronGST" and style_wav is not None:
         style_mel = compute_style_mel(style_wav, ap, use_cuda)
     # preprocess the given text