diff --git a/models/segmentation/cityscapes.py b/models/segmentation/cityscapes.py
index 80bbee7..5f1bee1 100644
--- a/models/segmentation/cityscapes.py
+++ b/models/segmentation/cityscapes.py
@@ -1,9 +1,11 @@
+import onnx
 import os
 import torch
 
 from mmengine.config import Config, DictAction
 from mmengine.runner import Runner
 from models.base import TorchModelWrapper
+from onnxsim import simplify
 
 class MmsegmentationModelWrapper(TorchModelWrapper):
     def load_model(self, eval=True):
@@ -43,4 +45,8 @@ def onnx_exporter(self, onnx_path):
         random_input = torch.randn(1,3,512,1024) # todo: support other input sizes
         if torch.cuda.is_available():
             random_input = random_input.cuda()
-        torch.onnx.export(self, random_input, onnx_path, verbose=False, keep_initializers_as_inputs=True)
\ No newline at end of file
+        torch.onnx.export(self, random_input, onnx_path, verbose=False, keep_initializers_as_inputs=True)
+
+        model = onnx.load(onnx_path)
+        model_simp, check = simplify(model)
+        onnx.save(model_simp, onnx_path)
\ No newline at end of file
diff --git a/optimiser_interface/utils.py b/optimiser_interface/utils.py
index ffeaeb1..d54d761 100644
--- a/optimiser_interface/utils.py
+++ b/optimiser_interface/utils.py
@@ -31,6 +31,7 @@ def opt_cli_launcher(model_name, onnx_path, output_dir,
     sys.argv += ['--objective', opt_obj]
     sys.argv += ['--optimiser', opt_solver]
     sys.argv += ['--optimiser_config_path', opt_cfg_path]
+    sys.argv += ['--custom_onnx']
     main()
     sys.argv = saved_argv