diff --git a/include/onnxruntime/core/session/onnxruntime_cxx_api.h b/include/onnxruntime/core/session/onnxruntime_cxx_api.h
index c6cb6ed36a..b6b7ca3a2d 100644
--- a/include/onnxruntime/core/session/onnxruntime_cxx_api.h
+++ b/include/onnxruntime/core/session/onnxruntime_cxx_api.h
@@ -979,17 +979,17 @@ struct CustomOpApi {
                     _In_ OrtOpAttrType type,
                     _Outptr_ OrtOpAttr** op_attr);
 
-  void ReleaseOpAttr(_In_ OrtOpAttr* op_attr);
+  void ReleaseOpAttr(_Frees_ptr_opt_ OrtOpAttr* op_attr);
 
   void CreateOp(_In_ const OrtKernelInfo* info,
                 _In_ const char* op_name,
                 _In_ const char* domain,
-                _In_ int version,
+                int version,
                 _In_opt_ const char** type_constraint_names,
                 _In_opt_ const ONNXTensorElementDataType* type_constraint_values,
-                _In_opt_ int type_constraint_count,
+                int type_constraint_count,
                 _In_opt_ const OrtOpAttr* const* attr_values,
-                _In_opt_ int attr_count,
+                int attr_count,
                 _Outptr_ OrtOp** ort_op);
 
   void InvokeOp(_In_ const OrtKernelContext* context,
@@ -999,7 +999,7 @@ struct CustomOpApi {
                 _Inout_ OrtValue* const* output_values,
                 _In_ int output_count);
 
-  void ReleaseOp(_In_ OrtOp* ort_op);
+  void ReleaseOp(_Frees_ptr_opt_ OrtOp* ort_op);
 
  private:
   const OrtApi& api_;
diff --git a/include/onnxruntime/core/session/onnxruntime_cxx_inline.h b/include/onnxruntime/core/session/onnxruntime_cxx_inline.h
index f944590c28..42c14ecc37 100644
--- a/include/onnxruntime/core/session/onnxruntime_cxx_inline.h
+++ b/include/onnxruntime/core/session/onnxruntime_cxx_inline.h
@@ -1221,12 +1221,12 @@ inline void CustomOpApi::ReleaseOpAttr(_Frees_ptr_opt_ OrtOpAttr* op_attr) {
 inline void CustomOpApi::CreateOp(_In_ const OrtKernelInfo* info,
                                   _In_ const char* op_name,
                                   _In_ const char* domain,
-                                  _In_ int version,
+                                  int version,
                                   _In_opt_ const char** type_constraint_names,
                                   _In_opt_ const ONNXTensorElementDataType* type_constraint_values,
-                                  _In_opt_ int type_constraint_count,
+                                  int type_constraint_count,
                                   _In_opt_ const OrtOpAttr* const* attr_values,
-                                  _In_opt_ int attr_count,
+                                  int attr_count,
                                   _Outptr_ OrtOp** ort_op) {
   ThrowOnError(api_.CreateOp(info, op_name, domain, version, type_constraint_names, type_constraint_values, type_constraint_count, attr_values, attr_count, ort_op));
 }
diff --git a/onnxruntime/core/session/ort_apis.h b/onnxruntime/core/session/ort_apis.h
index 4673260085..a56b85ee5b 100644
--- a/onnxruntime/core/session/ort_apis.h
+++ b/onnxruntime/core/session/ort_apis.h
@@ -357,12 +357,12 @@ ORT_API_STATUS_IMPL(CreateOp,
                     _In_ const OrtKernelInfo* info,
                     _In_ const char* op_name,
                     _In_ const char* domain,
-                    _In_ int version,
+                    int version,
                     _In_opt_ const char** type_constraint_names,
                     _In_opt_ const ONNXTensorElementDataType* type_constraint_values,
-                    _In_opt_ int type_constraint_count,
+                    int type_constraint_count,
                     _In_opt_ const OrtOpAttr* const* attr_values,
-                    _In_opt_ int attr_count,
+                    int attr_count,
                     _Outptr_ OrtOp** ort_op);
 
 ORT_API_STATUS_IMPL(InvokeOp,
diff --git a/onnxruntime/core/session/standalone_op_invoker.cc b/onnxruntime/core/session/standalone_op_invoker.cc
index c39541b3d9..6a43a8e516 100644
--- a/onnxruntime/core/session/standalone_op_invoker.cc
+++ b/onnxruntime/core/session/standalone_op_invoker.cc
@@ -355,12 +355,12 @@ ORT_API_STATUS_IMPL(OrtApis::CreateOp,
                     _In_ const OrtKernelInfo* info,
                     _In_ const char* op_name,
                     _In_ const char* domain,
-                    _In_ int version,
+                    int version,
                     _In_opt_ const char** type_constraint_names,
                     _In_opt_ const ONNXTensorElementDataType* type_constraint_values,
-                    _In_opt_ int type_constraint_count,
+                    int type_constraint_count,
                     _In_opt_ const OrtOpAttr* const* attr_values,
-                    _In_opt_ int attr_count,
+                    int attr_count,
                     _Outptr_ OrtOp** ort_op) {
   API_IMPL_BEGIN
   auto status = onnxruntime::standalone::CreateOp(info,