diff --git a/csharp/src/Microsoft.ML.OnnxRuntime/NativeMemoryAllocator.cs b/csharp/src/Microsoft.ML.OnnxRuntime/NativeMemoryAllocator.cs
index 87416440f8..0ff438e857 100644
--- a/csharp/src/Microsoft.ML.OnnxRuntime/NativeMemoryAllocator.cs
+++ b/csharp/src/Microsoft.ML.OnnxRuntime/NativeMemoryAllocator.cs
@@ -64,7 +64,7 @@ namespace Microsoft.ML.OnnxRuntime
 
         private static void Delete(IntPtr nativePtr)
         {
-            NativeMethods.ReleaseOrtAllocatorInfo(nativePtr);
+            NativeMethods.OrtReleaseAllocatorInfo(nativePtr);
         }
 
         protected override bool ReleaseHandle()
diff --git a/csharp/src/Microsoft.ML.OnnxRuntime/NativeMethods.cs b/csharp/src/Microsoft.ML.OnnxRuntime/NativeMethods.cs
index c7eb8d1f1f..4cf0ee85f0 100644
--- a/csharp/src/Microsoft.ML.OnnxRuntime/NativeMethods.cs
+++ b/csharp/src/Microsoft.ML.OnnxRuntime/NativeMethods.cs
@@ -170,11 +170,11 @@ namespace Microsoft.ML.OnnxRuntime
         [DllImport(nativeLib, CharSet = charSet)]
         public static extern IntPtr /*(OrtStatus*)*/ OrtCreateCUDAExecutionProviderFactory(int device_id, out IntPtr /*(OrtProviderFactoryPtr**)*/ factory);
 
-        [DllImport(nativeLib, CharSet = charSet)]
-        public static extern IntPtr /*(OrtStatus*)*/ OrtCreateNupharExecutionProviderFactory(int device_id, string target_str, out IntPtr /*(OrtProviderFactoryPtr**)*/ factory);
+        //[DllImport(nativeLib, CharSet = charSet)]
+        //public static extern IntPtr /*(OrtStatus*)*/ OrtCreateNupharExecutionProviderFactory(int device_id, string target_str, out IntPtr /*(OrtProviderFactoryPtr**)*/ factory);
 
-        [DllImport(nativeLib, CharSet = charSet)]
-        public static extern void OrtAddCustomOp(IntPtr /*(OrtSessionOptions*)*/ options, string custom_op_path);
+        //[DllImport(nativeLib, CharSet = charSet)]
+        //public static extern void OrtAddCustomOp(IntPtr /*(OrtSessionOptions*)*/ options, string custom_op_path);
 
         #endregion
 
@@ -215,7 +215,7 @@ namespace Microsoft.ML.OnnxRuntime
                                                         );
 
         [DllImport(nativeLib, CharSet = charSet)]
-        public static extern void ReleaseOrtAllocatorInfo(IntPtr /*(OrtAllocatorInfo*)*/ allocatorInfo);
+        public static extern void OrtReleaseAllocatorInfo(IntPtr /*(OrtAllocatorInfo*)*/ allocatorInfo);
 
         [DllImport(nativeLib, CharSet = charSet)]
         public static extern IntPtr /*(OrtStatus*)*/OrtCreateDefaultAllocator(out IntPtr /*(OrtAllocator**)*/ allocator);
@@ -258,12 +258,6 @@ namespace Microsoft.ML.OnnxRuntime
         [DllImport(nativeLib, CharSet = charSet)]
         public static extern IntPtr /*(OrtStatus*)*/ OrtGetTensorMutableData(IntPtr /*(OrtValue*)*/ value, out IntPtr /* (void**)*/ dataBufferHandle);
 
-        //[DllImport(nativeLib, CharSet = charSet)]
-        //public static extern IntPtr /*(OrtStatus*)*/ OrtGetTensorShapeDimCount(IntPtr /*(OrtValue*)*/ value, out ulong dimension); //size_t TODO: make it portable for x86, arm
-
-        //[DllImport(nativeLib, CharSet = charSet)]
-        //public static extern IntPtr /*(OrtStatus*)*/ OrtGetTensorShapeElementCount(IntPtr /*(OrtValue*)*/value, out ulong count);
-
         [DllImport(nativeLib, CharSet = charSet)]
         public static extern IntPtr /*(const struct OrtTensorTypeAndShapeInfo*)*/
                                 OrtCastTypeInfoToTensorInfo(IntPtr /*(struct OrtTypeInfo*)*/ typeInfo);
diff --git a/csharp/test/Microsoft.ML.OnnxRuntime.Tests/InferenceTest.cs b/csharp/test/Microsoft.ML.OnnxRuntime.Tests/InferenceTest.cs
index 6827545eb6..588c53e7be 100644
--- a/csharp/test/Microsoft.ML.OnnxRuntime.Tests/InferenceTest.cs
+++ b/csharp/test/Microsoft.ML.OnnxRuntime.Tests/InferenceTest.cs
@@ -5,6 +5,7 @@ using System;
 using System.IO;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.InteropServices;
 using System.Numerics.Tensors;
 using System.Threading.Tasks;
 using Xunit;
@@ -13,10 +14,12 @@ namespace Microsoft.ML.OnnxRuntime.Tests
 {
     public class InferenceTest
     {
+        private const string module = "onnxruntime.dll";
+
         [Fact]
         public void CanCreateAndDisposeSessionWithModelPath()
         {
-            string modelPath = Path.Combine(Directory.GetCurrentDirectory() , "squeezenet.onnx");
+            string modelPath = Path.Combine(Directory.GetCurrentDirectory(), "squeezenet.onnx");
             using (var session = new InferenceSession(modelPath))
             {
                 Assert.NotNull(session);
@@ -49,7 +52,7 @@ namespace Microsoft.ML.OnnxRuntime.Tests
         [Fact]
         private void CanRunInferenceOnAModel()
         {
-            string modelPath = Path.Combine(Directory.GetCurrentDirectory(),  "squeezenet.onnx");
+            string modelPath = Path.Combine(Directory.GetCurrentDirectory(), "squeezenet.onnx");
 
             using (var session = new InferenceSession(modelPath))
             {
@@ -121,7 +124,7 @@ namespace Microsoft.ML.OnnxRuntime.Tests
             var tensor = new DenseTensor<int>(inputDataInt, inputMeta["data_0"].Dimensions);
             container.Add(NamedOnnxValue.CreateFromTensor<int>("data_0", tensor));
             var ex = Assert.Throws<OnnxRuntimeException>(() => session.Run(container));
-            var msg = ex.ToString().Substring(0,101);
+            var msg = ex.ToString().Substring(0, 101);
             // TODO: message is diff in LInux. Use substring match
             Assert.Equal("Microsoft.ML.OnnxRuntime.OnnxRuntimeException: [ErrorCode:InvalidArgument] Unexpected input data type", msg);
             session.Dispose();
@@ -239,7 +242,7 @@ namespace Microsoft.ML.OnnxRuntime.Tests
                         var innodepair = inMeta.First();
                         var innodename = innodepair.Key;
                         var innodedims = innodepair.Value.Dimensions;
-                        for (int i=0; i < innodedims.Length; i++)
+                        for (int i = 0; i < innodedims.Length; i++)
                         {
                             if (innodedims[i] < 0)
                                 innodedims[i] = -1 * innodedims[i];
@@ -470,6 +473,40 @@ namespace Microsoft.ML.OnnxRuntime.Tests
             session.Dispose();
         }
 
+        [DllImport("kernel32", SetLastError = true)]
+        static extern IntPtr LoadLibrary(string lpFileName);
+
+        [DllImport("kernel32", CharSet = CharSet.Ansi)]
+        static extern UIntPtr GetProcAddress(IntPtr hModule, string procName);
+
+        [Fact]
+        private void VerifyNativeMethodsExist()
+        {
+            // Check for  external API changes
+            if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+                return;
+            var entryPointNames = new[]{
+            "OrtInitialize","OrtReleaseEnv","OrtGetErrorCode","OrtGetErrorMessage",
+            "OrtReleaseStatus","OrtCreateSession","OrtRun","OrtSessionGetInputCount",
+            "OrtSessionGetOutputCount","OrtSessionGetInputName","OrtSessionGetOutputName","OrtSessionGetInputTypeInfo",
+            "OrtSessionGetOutputTypeInfo","OrtReleaseSession","OrtCreateSessionOptions","OrtCloneSessionOptions",
+            "OrtEnableSequentialExecution","OrtDisableSequentialExecution","OrtEnableProfiling","OrtDisableProfiling",
+            "OrtEnableMemPattern","OrtDisableMemPattern","OrtEnableCpuMemArena","OrtDisableCpuMemArena",
+            "OrtSetSessionLogId","OrtSetSessionLogVerbosityLevel","OrtSetSessionThreadPoolSize","OrtSessionOptionsAppendExecutionProvider",
+            "OrtCreateCpuExecutionProviderFactory","OrtCreateAllocatorInfo","OrtCreateCpuAllocatorInfo",
+            "OrtCreateDefaultAllocator","OrtReleaseObject","OrtAllocatorFree","OrtAllocatorGetInfo",
+            "OrtCreateTensorWithDataAsOrtValue","OrtGetTensorMutableData", "OrtReleaseAllocatorInfo",
+            "OrtCastTypeInfoToTensorInfo","OrtGetTensorShapeAndType","OrtGetTensorElementType","OrtGetNumOfDimensions",
+            "OrtGetDimensions","OrtGetTensorShapeElementCount","OrtReleaseValue"};
+
+            var hModule = LoadLibrary(module);
+            foreach (var ep in entryPointNames)
+            {             
+                var x = GetProcAddress(hModule, ep);
+                Assert.False(x == UIntPtr.Zero, $"Entrypoint {ep} not found in module {module}");
+            }
+        }
+
         static float[] LoadTensorFromFile(string filename, bool skipheader = true)
         {
             var tensorData = new List<float>();