diff --git a/envoy/config/core/v3/grpc_service.proto b/envoy/config/core/v3/grpc_service.proto
index 3f62884d..967c694d 100644
--- a/envoy/config/core/v3/grpc_service.proto
+++ b/envoy/config/core/v3/grpc_service.proto
@@ -36,6 +36,12 @@ message GrpcService {
     // in the :ref:`Cluster <envoy_api_msg_config.cluster.v3.Cluster>` :ref:`transport_socket
     // <envoy_api_field_config.cluster.v3.Cluster.transport_socket>`.
     string cluster_name = 1 [(validate.rules).string = {min_bytes: 1}];
+
+    // The `:authority` header in the grpc request. If this field is not set, the authority header value will be `cluster_name`.
+    // Note that this authority does not override the SNI. The SNI is provided by the transport socket of the cluster.
+    string authority = 2
+        [(validate.rules).string =
+             {min_bytes: 0 max_bytes: 16384 well_known_regex: HTTP_HEADER_VALUE strict: false}];
   }
 
   // [#next-free-field: 9]
diff --git a/envoy/config/core/v4alpha/grpc_service.proto b/envoy/config/core/v4alpha/grpc_service.proto
index 4c95bb9e..51f11fa1 100644
--- a/envoy/config/core/v4alpha/grpc_service.proto
+++ b/envoy/config/core/v4alpha/grpc_service.proto
@@ -36,6 +36,12 @@ message GrpcService {
     // in the :ref:`Cluster <envoy_api_msg_config.cluster.v4alpha.Cluster>` :ref:`transport_socket
     // <envoy_api_field_config.cluster.v4alpha.Cluster.transport_socket>`.
     string cluster_name = 1 [(validate.rules).string = {min_bytes: 1}];
+
+    // The `:authority` header in the grpc request. If this field is not set, the authority header value will be `cluster_name`.
+    // Note that this authority does not override the SNI. The SNI is provided by the transport socket of the cluster.
+    string authority = 2
+        [(validate.rules).string =
+             {min_bytes: 0 max_bytes: 16384 well_known_regex: HTTP_HEADER_VALUE strict: false}];
   }
 
   // [#next-free-field: 9]