1 files changed, 3 insertions, 1 deletions
diff --git a/src/csharp/Grpc.Core/ChannelOptions.cs b/src/csharp/Grpc.Core/ChannelOptions.cs
index 9fe03d2805..1e0f90287a 100644
--- a/src/csharp/Grpc.Core/ChannelOptions.cs
+++ b/src/csharp/Grpc.Core/ChannelOptions.cs
@@ -30,7 +30,6 @@
 #endregion
 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Runtime.InteropServices;
 using System.Threading;
 using System.Threading.Tasks;
@@ -135,6 +134,9 @@ namespace Grpc.Core
         /// <summary>Initial sequence number for http2 transports</summary>
         public const string Http2InitialSequenceNumber = "grpc.http2.initial_sequence_number";
 
+        /// <summary>Default authority for calls.</summary>
+        public const string DefaultAuthority = "grpc.default_authority";
+
         /// <summary>Primary user agent: goes at the start of the user-agent metadata</summary>
         public const string PrimaryUserAgentString = "grpc.primary_user_agent";