diff --git a/mmdeploy/__init__.py b/mmdeploy/__init__.py
index e6064085a..4dcdfd926 100644
--- a/mmdeploy/__init__.py
+++ b/mmdeploy/__init__.py
@@ -1,17 +1,17 @@
-import logging
 import importlib
+import logging
 
-if importlib.util.find_spec("mmcls"):
+if importlib.util.find_spec('mmcls'):
     from .mmcls import *  # noqa: F401,F403
 else:
     logging.debug('mmcls is not installed.')
 
-if importlib.util.find_spec("mmdet"):
+if importlib.util.find_spec('mmdet'):
     from .mmdet import *  # noqa: F401,F403
 else:
     logging.debug('mmdet is not installed.')
 
-if importlib.util.find_spec("mmseg"):
+if importlib.util.find_spec('mmseg'):
     from .mmseg import *  # noqa: F401,F403
 else:
     logging.debug('mmseg is not installed.')
diff --git a/mmdeploy/utils/function_rewriter.py b/mmdeploy/utils/function_rewriter.py
index a7dce49a9..6f6d2b9fd 100644
--- a/mmdeploy/utils/function_rewriter.py
+++ b/mmdeploy/utils/function_rewriter.py
@@ -52,7 +52,8 @@ def register_rewriter(func_name: str,
         func_args.update(kwargs)
         func_caller = type(func_name + '@' + backend, (FuncCaller, ),
                            func_args)
-        return FUNCTION_REWRITERS.register_module()(func_caller)
+        FUNCTION_REWRITERS.register_module()(func_caller)
+        return func
 
     return wrap
 
diff --git a/mmdeploy/utils/symbolic_register.py b/mmdeploy/utils/symbolic_register.py
index e51d9852e..bb6e1584f 100644
--- a/mmdeploy/utils/symbolic_register.py
+++ b/mmdeploy/utils/symbolic_register.py
@@ -79,7 +79,8 @@ def register_symbolic(func_name: str,
         symbolic_args.update(kwargs)
         wrapper_name = '@'.join([func_name, backend, str(is_pytorch)])
         wrapper = type(wrapper_name, (SymbolicWrapper, ), symbolic_args)
-        return SYMBOLICS_REGISTER.register_module(wrapper_name)(wrapper)
+        SYMBOLICS_REGISTER.register_module(wrapper_name)(wrapper)
+        return symbolic_impl
 
     return wrapper
 
diff --git a/tests/test_utils/test_register.py b/tests/test_utils/test_register.py
index 4663ba085..bdfd2c55e 100644
--- a/tests/test_utils/test_register.py
+++ b/tests/test_utils/test_register.py
@@ -9,6 +9,8 @@ def test_function_rewriter():
     x = torch.tensor([1, 2, 3, 4, 5])
     y = torch.tensor([2, 4, 6, 8, 10])
 
+    @FUNCTION_REWRITERS.register_rewriter(
+        func_name='torch.mul', backend='tensorrt')
     @FUNCTION_REWRITERS.register_rewriter(
         func_name='torch.add', backend='tensorrt')
     def sub_func(rewriter, x, y):
@@ -21,6 +23,9 @@ def test_function_rewriter():
         result = torch.add(x, y)
         # replace add with sub
         torch.testing.assert_allclose(result, x - y)
+        result = torch.mul(x, y)
+        # replace add with sub
+        torch.testing.assert_allclose(result, x - y)
 
     result = torch.add(x, y)
     # recovery origin function
@@ -120,6 +125,7 @@ def test_symbolic_register():
     mmdeploy.TestFunc = TestFunc
     test_func = mmdeploy.TestFunc.apply
 
+    @SYMBOLICS_REGISTER.register_symbolic('mmdeploy.TestFunc', backend='ncnn')
     @SYMBOLICS_REGISTER.register_symbolic('mmdeploy.TestFunc')
     def symbolic_testfunc_default(symbolic_wrapper, g, x, val):
         assert hasattr(symbolic_wrapper, 'cfg')
@@ -161,8 +167,18 @@ def test_symbolic_register():
     assert nodes[1].op_type == 'cummax_default'
     assert nodes[1].domain == 'mmcv'
 
+    # ncnn
+    register_extra_symbolics(cfg=cfg, backend='ncnn', opset=11)
+    torch.onnx.export(model, x, output_file, opset_version=11)
+    onnx_model = onnx.load(output_file)
+    os.remove(output_file)
+    nodes = onnx_model.graph.node
+    assert nodes[0].op_type == 'symbolic_testfunc_default'
+    assert nodes[0].domain == 'mmcv'
+    assert nodes[1].op_type == 'cummax_default'
+    assert nodes[1].domain == 'mmcv'
+
     # default
-    cfg = dict()
     register_extra_symbolics(cfg=cfg, backend='tensorrt', opset=11)
     torch.onnx.export(model, x, output_file, opset_version=11)
     onnx_model = onnx.load(output_file)