diff --git a/grpc.go b/grpc.go
index 360fdd1..b36ee71 100644
--- a/grpc.go
+++ b/grpc.go
@@ -759,6 +759,8 @@ func (g *grpcServer) Register() error {
 	}
 	g.RUnlock()
 
+	service.Metadata["protocol"] = "grpc"
+	service.Metadata["transport"] = "grpc"
 	service.Endpoints = endpoints
 
 	g.RLock()