diff --git a/protos/Makefile b/protos/Makefile
index 6f7ed0b..2618db3 100644
--- a/protos/Makefile
+++ b/protos/Makefile
@@ -18,9 +18,8 @@
 # OpenOLT Proto version.
 # This specifies the GIT tag in https://github.com/opencord/voltha-protos
 # repo that we need to refer to, to pick the right version of
-# openolt.proto and tech_profile.proto
-OPENOLT_PROTO_VER ?= v3.4.5
-GRPC_VER ?= v1.10.x
+# openolt.proto, ext_config.proto and tech_profile.proto
+OPENOLT_PROTO_VER ?= v4.0.2
 
 CXX ?= g++
 CPPFLAGS += `pkg-config --cflags protobuf grpc` -I googleapis/gens -I./
@@ -30,7 +29,7 @@
 GRPC_CPP_PLUGIN = grpc_cpp_plugin
 GRPC_CPP_PLUGIN_PATH ?= $(shell which grpc_cpp_plugin)
 
-OBJS = voltha_protos/common.pb.o voltha_protos/common.grpc.pb.o voltha_protos/tech_profile.pb.o voltha_protos/tech_profile.grpc.pb.o voltha_protos/openolt.pb.o voltha_protos/openolt.grpc.pb.o voltha_protos/ext_config.grpc.pb.o  voltha_protos/ext_config.pb.o ./googleapis/gens/google/api/annotations.grpc.pb.o ./googleapis/gens/google/api/annotations.pb.o ./googleapis/gens/google/api/http.pb.o
+OBJS = voltha_protos/common.pb.o voltha_protos/common.grpc.pb.o voltha_protos/tech_profile.pb.o voltha_protos/tech_profile.grpc.pb.o voltha_protos/ext_config.pb.o voltha_protos/ext_config.grpc.pb.o voltha_protos/openolt.pb.o voltha_protos/openolt.grpc.pb.o ./googleapis/gens/google/api/annotations.grpc.pb.o ./googleapis/gens/google/api/annotations.pb.o ./googleapis/gens/google/api/http.pb.o
 
 .DEFAULT_GOAL := all