diff --git a/tests/test_codebase/test_mmdet/test_mmdet_models.py b/tests/test_codebase/test_mmdet/test_mmdet_models.py
index 368f5d4db..4809f10c7 100644
--- a/tests/test_codebase/test_mmdet/test_mmdet_models.py
+++ b/tests/test_codebase/test_mmdet/test_mmdet_models.py
@@ -112,6 +112,15 @@ def get_fcos_head_model():
     return model
 
 
+def get_l2norm_forward_model():
+    """L2Norm Neck Config."""
+    from mmdet.models.necks.ssd_neck import L2Norm
+    model = L2Norm(16)
+
+    model.requires_grad_(False)
+    return model
+
+
 def get_rpn_head_model():
     """RPN Head Config."""
     test_cfg = mmcv.Config(
@@ -139,6 +148,43 @@ def get_single_roi_extractor():
     return model
 
 
+@pytest.mark.parametrize('backend_type', [Backend.ONNXRUNTIME])
+def test_l2norm_forward(backend_type):
+    check_backend(backend_type)
+    l2norm_neck = get_l2norm_forward_model()
+    l2norm_neck.cpu().eval()
+    s = 128
+    deploy_cfg = mmcv.Config(
+        dict(
+            backend_config=dict(type=backend_type.value),
+            onnx_config=dict(input_shape=None)))
+    feat = torch.rand(1, 16, s, s)
+    model_outputs = [l2norm_neck.forward(feat)]
+    wrapped_model = WrapModel(l2norm_neck, 'forward')
+    rewrite_inputs = {
+        'x': feat,
+    }
+    rewrite_outputs, is_backend_output = get_rewrite_outputs(
+        wrapped_model=wrapped_model,
+        model_inputs=rewrite_inputs,
+        deploy_cfg=deploy_cfg)
+
+    if is_backend_output:
+        for model_output, rewrite_output in zip(model_outputs[0],
+                                                rewrite_outputs[0]):
+            model_output = model_output.squeeze().cpu().numpy()
+            rewrite_output = rewrite_output.squeeze()
+            assert np.allclose(
+                model_output, rewrite_output, rtol=1e-03, atol=1e-05)
+    else:
+        for model_output, rewrite_output in zip(model_outputs[0],
+                                                rewrite_outputs[0]):
+            model_output = model_output.squeeze().cpu().numpy()
+            rewrite_output = rewrite_output.squeeze()
+            assert np.allclose(
+                model_output[0], rewrite_output, rtol=1e-03, atol=1e-05)
+
+
 def test_get_bboxes_of_fcos_head_ncnn():
     backend_type = Backend.NCNN
     check_backend(backend_type)