diff --git a/runtime/onnion_runtime/convtranspose.py b/runtime/onnion_runtime/convtranspose.py
index a6e826c..2b71c4e 100644
--- a/runtime/onnion_runtime/convtranspose.py
+++ b/runtime/onnion_runtime/convtranspose.py
@@ -40,7 +40,7 @@ def run(self, x: np.ndarray, W: np.ndarray, b: Optional[np.ndarray] = None) -> L
 
         # define parameters
         dim = len(x.shape) - 2
-        group = self.group or 1
+        group = self.group
         batch = x.shape[0]
         in_ch = x.shape[1]
         out_ch = W.shape[1]