address comment
diff --git a/cpp/helloworld/Makefile b/cpp/helloworld/Makefile
index e6ddb64..0333cc2 100644
--- a/cpp/helloworld/Makefile
+++ b/cpp/helloworld/Makefile
@@ -32,7 +32,7 @@
 CXX = g++
 CPPFLAGS = -I/usr/local/include -pthread
 CXXFLAGS = -std=c++11
-LDFLAGS = -L/usr/local/lib -lgrpc -lgrpc++_unsecure -lprotobuf -lpthread -ldl
+LDFLAGS = -L/usr/local/lib -lgrpc++_unsecure -lgrpc -lgpr -lprotobuf -lpthread -ldl
 PROTOC = protoc
 GRPC_CPP_PLUGIN = grpc_cpp_plugin
 GRPC_CPP_PLUGIN_PATH ?= `which $(GRPC_CPP_PLUGIN)`