diff --git a/agent/test/Makefile.in b/agent/test/Makefile.in
index ffe5e3b..2122266 100644
--- a/agent/test/Makefile.in
+++ b/agent/test/Makefile.in
@@ -22,6 +22,11 @@
 TOP_DIR=`pwd`
 OPENOLTDEVICE ?= asfvolt16
 
+# 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
 
 # GRPC installation
 GRPC_ADDR = https://github.com/grpc/grpc
@@ -47,7 +52,7 @@
 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
 
 BAL_API_DIR=bal-api-3.1.0
 BALLIBNAME=bcm_host_api_stubs
diff --git a/agent/test/README.md b/agent/test/README.md
index 1840e61..5ec0013 100644
--- a/agent/test/README.md
+++ b/agent/test/README.md
@@ -20,6 +20,16 @@
 # This will build and run the unit test cases
 $ make test
 ```
+
+If you need to use a specific version of voltha-protos, then specify the git tag/branch corresponding to
+tht specific version as below. For ex:
+
+```
+make OPENOLT_PROTO_VER=master test
+```
+
+By default, the OPENOLT_PROTO_VER defaults to git tag *v1.0.3* of https://github.com/opencord/voltha-protos repo.
+
 Once you have successfully built and run the unit-test, the test report will be available in `test_openolt_report.xml` file in `agent/test`.
 To clean all build artifacts and test reports, do `make clean` in `agent/test`.