diff --git a/imperative/python/test/unit/core/test_function.py b/imperative/python/test/unit/core/test_function.py
index 84153b58a165b9e9ee903badb1ebe92ce88fc4af..1906a985b7967b8ad55a4fb34764dc53d701b465 100644
--- a/imperative/python/test/unit/core/test_function.py
+++ b/imperative/python/test/unit/core/test_function.py
@@ -8,6 +8,7 @@
 import copy
 
 import numpy as np
+import pytest
 
 import megengine.autodiff as ad
 import megengine.functional as F
@@ -303,3 +304,17 @@ def test_zero_grad():
     np.testing.assert_almost_equal(
         net.a.numpy(), np.array([1.0 - 4.0], dtype=np.float32),
     )
+
+
+def test_throw_on_non_tensor_argument():
+    class NonTensorArg(Function):
+        def forward(self, inp, c):
+            return inp + c
+
+        def backward(self, grad):
+            return grad
+
+    x = tensor(np.array([2.33], dtype=np.float32))
+    func = NonTensorArg()
+    with pytest.raises(TypeError, match=r"op .* expect type Tensor as inputs"):
+        func(x, 1)
diff --git a/imperative/src/impl/op_trait.h b/imperative/src/impl/op_trait.h
index 93e5c397250721cede911cd637a4e989751d5428..850f23466f2bfb460f6c453861002d3d077aea82 100644
--- a/imperative/src/impl/op_trait.h
+++ b/imperative/src/impl/op_trait.h
@@ -108,7 +108,7 @@ struct OpMethNotImpl {
 struct OpMethFallback : public OpMethNotImpl {
     using OpMethNotImpl::impl;
     static void impl(ApplyOnPhysicalTensor& func,
-                                         op_meth_tag::ApplyOnPhysicalTensor);
+                     op_meth_tag::ApplyOnPhysicalTensor);
     static void impl(Execute& func, op_meth_tag::Execute);
     static void impl(InferOutputMemDesc& func, op_meth_tag::InferOutputMemDesc);
     static void impl(InferOutputAttrsFallible& func,
@@ -120,9 +120,9 @@ struct OpMethFallback : public OpMethNotImpl {
 template <typename Tag, typename RType, typename... Args>
 struct OpMeth<Tag, RType(Args...)> : public thin_function<RType(Args...)> {
     using Base = thin_function<RType(Args...)>;
-    using Base::operator bool;
     OpMeth() : Base{}, allow_fallback(false){};
     explicit OpMeth(const Base& base) { this->Base::operator=(base); }
+    using Base::operator bool;
     RType operator()(Args... args) const {
         if (!this->Base::operator bool()) {
             if (allow_fallback) {