diff --git a/wekws/bin/export_onnx.py b/wekws/bin/export_onnx.py
index 75eb5b0..8121830 100644
--- a/wekws/bin/export_onnx.py
+++ b/wekws/bin/export_onnx.py
@@ -49,8 +49,9 @@ def main():
     dummy_input = torch.randn(1, 100, feature_dim, dtype=torch.float)
     cache = torch.zeros(1,
                         model.hdim,
-                        model.backbone.padding,
+                        0,
                         dtype=torch.float)
+
     torch.onnx.export(model, (dummy_input, cache),
                       args.onnx_model,
                       input_names=['input', 'cache'],
@@ -71,7 +72,7 @@ def main():
     meta = onnx_model.metadata_props.add()
     meta.key, meta.value = 'cache_dim', str(model.hdim)
     meta = onnx_model.metadata_props.add()
-    meta.key, meta.value = 'cache_len', str(model.backbone.padding)
+    meta.key, meta.value = 'cache_len', str(0)
     onnx.save(onnx_model, args.onnx_model)
 
     # Verify onnx precision