diff --git a/src/csharp/Grpc.Auth/GoogleCredential.cs b/src/csharp/Grpc.Auth/GoogleCredential.cs
index 7385a264857..3e31755bfc2 100644
--- a/src/csharp/Grpc.Auth/GoogleCredential.cs
+++ b/src/csharp/Grpc.Auth/GoogleCredential.cs
@@ -33,18 +33,13 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.IO;
-using System.Threading.Tasks;
-using Grpc.Core;
-using Grpc.Core.Utils;
+using System.Security.Cryptography;
 
 using Google.Apis.Auth.OAuth2;
-using System.Security.Cryptography.X509Certificates;
-using Newtonsoft.Json.Linq;
 using Mono.Security.Cryptography;
+using Newtonsoft.Json.Linq;
 using Org.BouncyCastle.Crypto.Parameters;
-using System.Security.Cryptography;
 using Org.BouncyCastle.Security;
 
 namespace Grpc.Auth
diff --git a/src/csharp/Grpc.Auth/OAuth2InterceptorFactory.cs b/src/csharp/Grpc.Auth/OAuth2InterceptorFactory.cs
index 8a1e87ad6fc..ae4a987dcba 100644
--- a/src/csharp/Grpc.Auth/OAuth2InterceptorFactory.cs
+++ b/src/csharp/Grpc.Auth/OAuth2InterceptorFactory.cs
@@ -35,14 +35,14 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.Security.Cryptography.X509Certificates;
 using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
-using Grpc.Core;
-using Grpc.Core.Utils;
 
 using Google.Apis.Auth.OAuth2;
-using System.Security.Cryptography.X509Certificates;
+using Grpc.Core;
+using Grpc.Core.Utils;
 
 namespace Grpc.Auth
 {
@@ -54,9 +54,8 @@ namespace Grpc.Auth
             credential.RequestAccessTokenAsync(CancellationToken.None).Wait();
             string accessToken = credential.Token.AccessToken;
 
-            // TODO: token refresh logic!!
+            // TODO(jtattermusch): implement token refresh logic!!
             return new HeaderInterceptorDelegate((b) => { b.Add(new Metadata.MetadataEntry("Authorization", "Bearer " + accessToken)); });
-
         }
     }
 }
diff --git a/src/csharp/Grpc.IntegrationTesting/InteropClient.cs b/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
index 20ecd60c303..3b909de0135 100644
--- a/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
+++ b/src/csharp/Grpc.IntegrationTesting/InteropClient.cs
@@ -33,21 +33,14 @@
 
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
-using System.IO;
 using System.Text.RegularExpressions;
-using System.Threading.Tasks;
+
 using Google.ProtocolBuffers;
 using grpc.testing;
 using Grpc.Auth;
 using Grpc.Core;
 using Grpc.Core.Utils;
 using NUnit.Framework;
-using Newtonsoft.Json.Linq;
-using System.Threading;
-
-using Google.Apis.Auth.OAuth2;
-using System.Security.Cryptography.X509Certificates;
 
 namespace Grpc.IntegrationTesting
 {