adjust C# generator to match the new API
diff --git a/src/csharp/Grpc.IntegrationTesting/InteropClient.cs b/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
index bdcb2c5..4fd9dda 100644
--- a/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
+++ b/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
@@ -119,7 +119,7 @@
 
             using (Channel channel = new Channel(options.serverHost, options.serverPort.Value, credentials, channelOptions))
             {
-                var stubConfig = StubConfiguration.Default;
+                TestService.TestServiceClient client = new TestService.TestServiceClient(channel);
                 if (options.testCase == "service_account_creds" || options.testCase == "compute_engine_creds")
                 {
                     var credential = GoogleCredential.GetApplicationDefault();
@@ -127,10 +127,9 @@
                     {
                         credential = credential.CreateScoped(new[] { AuthScope });
                     }
-                    stubConfig = new StubConfiguration(OAuth2InterceptorFactory.Create(credential));
+                    client.HeaderInterceptor = OAuth2InterceptorFactory.Create(credential);
                 }
 
-                TestService.ITestServiceClient client = new TestService.TestServiceClient(channel, stubConfig);
                 RunTestCase(options.testCase, client);
             }
             GrpcEnvironment.Shutdown();
diff --git a/src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs b/src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs
index 6c2da9d..f306289 100644
--- a/src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs
+++ b/src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs
@@ -65,7 +65,7 @@
                 new ChannelOption(ChannelOptions.SslTargetNameOverride, TestCredentials.DefaultHostOverride)
             };
             channel = new Channel(host, port, TestCredentials.CreateTestClientCredentials(true), options);
-            client = TestService.NewStub(channel);
+            client = TestService.NewClient(channel);
         }
 
         [TestFixtureTearDown]
diff --git a/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs b/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
index 35b9b3d..8502bb5 100644
--- a/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
+++ b/src/csharp/Grpc.IntegrationTesting/TestGrpc.cs
@@ -56,7 +56,7 @@
         __Marshaller_StreamingOutputCallRequest,
         __Marshaller_StreamingOutputCallResponse);
 
-    // client-side stub interface
+    // client interface
     public interface ITestServiceClient
     {
       global::grpc.testing.Empty EmptyCall(global::grpc.testing.Empty request, CancellationToken token = default(CancellationToken));
@@ -81,12 +81,9 @@
     }
 
     // client stub
-    public class TestServiceClient : ClientBase<TestServiceClient, StubConfiguration>, ITestServiceClient
+    public class TestServiceClient : ClientBase, ITestServiceClient
     {
-      public TestServiceClient(Channel channel) : this(channel, StubConfiguration.Default)
-      {
-      }
-      public TestServiceClient(Channel channel, StubConfiguration config) : base(channel, config)
+      public TestServiceClient(Channel channel) : base(channel)
       {
       }
       public global::grpc.testing.Empty EmptyCall(global::grpc.testing.Empty request, CancellationToken token = default(CancellationToken))
@@ -143,17 +140,12 @@
           .AddMethod(__Method_HalfDuplexCall, serviceImpl.HalfDuplexCall).Build();
     }
 
-    // creates a new client stub
-    public static ITestServiceClient NewStub(Channel channel)
+    // creates a new client
+    public static TestServiceClient NewClient(Channel channel)
     {
       return new TestServiceClient(channel);
     }
 
-    // creates a new client stub
-    public static ITestServiceClient NewStub(Channel channel, StubConfiguration config)
-    {
-      return new TestServiceClient(channel, config);
-    }
   }
 }
 #endregion