diff --git a/mace/python/tools/tf_converter_lib.py b/mace/python/tools/tf_converter_lib.py
index d562228ffd51bf7895582dc5af4c48dbd59a8aef..08107b55d40ace47e057580d2fcc93d5867bb439 100644
--- a/mace/python/tools/tf_converter_lib.py
+++ b/mace/python/tools/tf_converter_lib.py
@@ -406,7 +406,7 @@ class TFConverter(object):
         input_channels = weight_tensor_value.shape[2]
         # HWIO -> OIHW
         weight_tensor_value = weight_tensor_value.transpose(3, 2, 0, 1)
-        if input_shape[2] > 16 and input_shape[3] > 16:
+        if input_shape[1] > 16 and input_shape[2] > 16:
             G = np.array([
                 [1.0, 0.0, 0.0],
                 [-2.0 / 9, -2.0 / 9, -2.0 / 9],