diff --git a/deepspeech/models/u2.py b/deepspeech/models/u2.py
index 46d932c9841905aee096a1a61196f53e6f276d64..fd8f154716459d109bdec3cb482fdc41ffc27ee8 100644
--- a/deepspeech/models/u2.py
+++ b/deepspeech/models/u2.py
@@ -115,7 +115,8 @@ class U2BaseModel(nn.Layer):
                  ctc_weight: float=0.5,
                  ignore_id: int=IGNORE_ID,
                  lsm_weight: float=0.0,
-                 length_normalized_loss: bool=False):
+                 length_normalized_loss: bool=False,
+                 **kwargs):
         assert 0.0 <= ctc_weight <= 1.0, ctc_weight
 
         super().__init__()