diff --git a/onnxconverter_common/onnx2py.py b/onnxconverter_common/onnx2py.py
index beacf1a..b4630ca 100644
--- a/onnxconverter_common/onnx2py.py
+++ b/onnxconverter_common/onnx2py.py
@@ -15,8 +15,9 @@
 import sys
 import onnx
 import collections
+import inspect
 from collections import OrderedDict
-from onnx import helper, numpy_helper, TensorProto
+from onnx import helper, numpy_helper, TensorProto, external_data_helper
 import numpy as np
 import os
 
@@ -33,6 +34,30 @@
 os_traced = TracingObject("os")
 
 
+# <Helpers> These can be inlined into the output script #
+
+def clear_field(proto, field):
+    proto.ClearField(field)
+    return proto
+
+
+def make_external_tensor(name, data_type, dims, raw_data=None, **kwargs):
+    tensor = TensorProto()
+    tensor.data_type = data_type
+    tensor.name = name
+    tensor.dims.extend(dims)
+    if raw_data is not None:
+        tensor.raw_data = raw_data
+    external_data_helper.set_external_data(tensor, **kwargs)
+    return tensor
+
+# </Helpers> #
+
+
+clear_field_traced = TracingObject("clear_field")
+make_external_tensor_traced = TracingObject("make_external_tensor")
+
+
 def convert_tensor_type(i):
     return getattr(TensorProtoTraced, TensorProto.DataType.Name(i))
 
@@ -90,13 +115,28 @@ def convert_shape_denotation(d):
 
 
 def convert_operatorsetid(opsetid):
-    domain = opsetid.domain
     version = opsetid.version
-    return helper_traced.make_operatorsetid(domain, version)
+    if opsetid.HasField("domain"):
+        domain = opsetid.domain
+        return helper_traced.make_operatorsetid(domain, version)
+    else:
+        return clear_field_traced(helper_traced.make_operatorsetid('', version), 'domain')
+
+
+def convert_external_tensor(tensor):
+    kwargs = OrderedDict()
+    if tensor.HasField("raw_data"):
+        kwargs["raw_data"] = tensor.raw_data
+    if tensor.external_data:
+        for d in tensor.external_data:
+            kwargs[d.key] = d.value
+    return make_external_tensor_traced(tensor.name, tensor.data_type, tensor.dims, **kwargs)
 
 
 def convert_tensor(tensor):
     global const_dir, const_counter
+    if tensor.data_location == TensorProto.EXTERNAL:
+        return convert_external_tensor(tensor)
     np_data = numpy_helper.to_array(tensor)
     if np.product(np_data.shape) <= 10:
         return numpy_helper_traced.from_array(np_data, name=tensor.name)
@@ -169,15 +209,24 @@ def convert(model, out_path):
     const_dir = out_path
     const_dir_name = os.path.basename(out_path)
     const_counter = 0
+    TracingObject.reset_cnt(clear_field_traced)
+    TracingObject.reset_cnt(make_external_tensor_traced)
 
     model_trace = convert_model(model)
-    code = "from onnx import helper, numpy_helper, TensorProto\n"
+    code = "from onnx import helper, numpy_helper, TensorProto"
+    if TracingObject.get_cnt(make_external_tensor_traced):
+        code += ", external_data_helper"
+    code += "\n"
     code += "import onnx\n"
     code += "import numpy as np\n"
     code += "import sys\n"
     if os.path.exists(const_dir):
         code += "import os\n"
         code += "\nDATA_DIR = os.path.join(os.path.dirname(os.path.realpath(__file__)), %r)\n" % const_dir_name
+    if TracingObject.get_cnt(clear_field_traced):
+        code += "\n" + inspect.getsource(clear_field)
+    if TracingObject.get_cnt(make_external_tensor_traced):
+        code += "\n" + inspect.getsource(make_external_tensor)
     code += "\n" + "model = " + repr(model_trace) + "\n"
     code += "\nif __name__ == '__main__' and len(sys.argv) == 2:\n"
     code += "    _, out_path = sys.argv\n"
@@ -193,7 +242,7 @@ def main():
     if not out_path.endswith(".py"):
         out_path = out_path + ".py"
 
-    model = onnx.load(in_path)
+    model = onnx.load(in_path, load_external_data=False)
     try:
         convert(model, out_path)
     except MissingHandlerException as e:
diff --git a/onnxconverter_common/pytracing.py b/onnxconverter_common/pytracing.py
index c0a7d16..e5901ba 100644
--- a/onnxconverter_common/pytracing.py
+++ b/onnxconverter_common/pytracing.py
@@ -20,6 +20,15 @@ class TracingObject:
     """
     def __init__(self, trace):
         self._trace = trace
+        self._cnt = 0
+
+    @staticmethod
+    def reset_cnt(o):
+        o._cnt = 0
+
+    @staticmethod
+    def get_cnt(o):
+        return o._cnt
 
     @staticmethod
     def from_repr(o):
@@ -38,9 +47,11 @@ def get_repr(x):
         return "[\n" + "".join(indent(s) + ",\n" for s in ls) + "]"
 
     def __getattr__(self, attr):
+        self._cnt += 1
         return TracingObject(self._trace + "." + attr)
 
     def __call__(self, *args, **kwargs):
+        self._cnt += 1
         arg_s = [TracingObject.get_repr(o) for o in args]
         arg_s += [k + "=" + TracingObject.get_repr(o) for k, o in kwargs.items()]
         trace = self._trace + "(" + ", ".join(arg_s) + ")"
diff --git a/tests/test_onnx2py.py b/tests/test_onnx2py.py
index c1e47a4..6b56dce 100644
--- a/tests/test_onnx2py.py
+++ b/tests/test_onnx2py.py
@@ -5,14 +5,13 @@
 import onnxruntime as _ort
 import sys
 
-from onnxconverter_common.onnx2py import convert, clear_directory
-
 working_path = os.path.abspath(os.path.dirname(__file__))
 tmp_path = os.path.join(working_path, 'temp')
 data_path = os.path.join(working_path, 'data')
 
 class Oonnx2PyTests(unittest.TestCase):
     def tearDown(self):
+        from onnxconverter_common.onnx2py import clear_directory
         for f in os.listdir(tmp_path):
             if f.endswith(".py"):
                 os.remove(os.path.join(tmp_path, f))
@@ -22,7 +21,7 @@ def tearDown(self):
 
     @unittest.skipIf(sys.version_info < (3, 6), "Requires onnx > 1.3.0")
     def test_onnx2py(self):
-        global model
+        from onnxconverter_common.onnx2py import convert
         model_name = 'test_model_1_no_opt'
         onnx_model = onnx.load(os.path.join(data_path, model_name + '.onnx'))
         sess1 = _ort.InferenceSession(onnx_model.SerializeToString())