diff --git a/agent/Makefile.in b/agent/Makefile.in
index bd4e3da..09338b0 100644
--- a/agent/Makefile.in
+++ b/agent/Makefile.in
@@ -38,6 +38,13 @@
 #
 # Version of Open Network Linux (ONL).
 ONL_KERN_VER_MAJOR = 4.14
+
+# 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 ?= v1.0.3
+
 #
 # Build directory
 BUILD_DIR = build
@@ -70,7 +77,7 @@
 LDFLAGS += `pkg-config --libs protobuf grpc++ grpc` -ldl -lgpr
 CXXFLAGSDEVICE = -I./device -I./device/$(OPENOLTDEVICE) -I./device/generic
 
-export CXX CXXFLAGS
+export CXX CXXFLAGS OPENOLT_PROTO_VER
 
 prereq:
 	sudo apt-get -q -y install git pkg-config build-essential autoconf libtool libgflags-dev libgtest-dev clang libc++-dev unzip docker.io