diff --git a/qlib/contrib/model/pytorch_lstm_ts.py b/qlib/contrib/model/pytorch_lstm_ts.py
index 26409011f..79987ee0f 100755
--- a/qlib/contrib/model/pytorch_lstm_ts.py
+++ b/qlib/contrib/model/pytorch_lstm_ts.py
@@ -58,7 +58,7 @@ class LSTM(Model):
         loss="mse",
         optimizer="adam",
         n_jobs=10,
-        GPU="0",
+        GPU=0,
         seed=None,
         **kwargs
     ):