diff --git a/clientconn.go b/clientconn.go
index e0d6f4666..f58740b25 100644
--- a/clientconn.go
+++ b/clientconn.go
@@ -444,6 +444,20 @@ func (csm *connectivityStateManager) getNotifyChan() <-chan struct{} {
 	return csm.notifyChan
 }
 
+// ClientConnInterface defines the functions clients need to perform unary and
+// streaming RPCs.  It is implemented by *ClientConn, and is only intended to
+// be referenced by generated code.
+type ClientConnInterface interface {
+	// Invoke performs a unary RPC and returns after the response is received
+	// into reply.
+	Invoke(ctx context.Context, method string, args interface{}, reply interface{}, opts ...CallOption) error
+	// NewStream begins a streaming RPC.
+	NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error)
+}
+
+// Assert *ClientConn implements ClientConnInterface.
+var _ ClientConnInterface = (*ClientConn)(nil)
+
 // ClientConn represents a virtual connection to a conceptual endpoint, to
 // perform RPCs.
 //
diff --git a/rpc_util.go b/rpc_util.go
index edaba7957..d3a4adc5e 100644
--- a/rpc_util.go
+++ b/rpc_util.go
@@ -871,7 +871,7 @@ type channelzData struct {
 
 // The SupportPackageIsVersion variables are referenced from generated protocol
 // buffer files to ensure compatibility with the gRPC version used.  The latest
-// support package version is 5.
+// support package version is 6.
 //
 // Older versions are kept for compatibility. They may be removed if
 // compatibility cannot be maintained.
@@ -881,6 +881,7 @@ const (
 	SupportPackageIsVersion3 = true
 	SupportPackageIsVersion4 = true
 	SupportPackageIsVersion5 = true
+	SupportPackageIsVersion6 = true
 )
 
 const grpcUA = "grpc-go/" + Version