diff --git a/protos/Makefile b/protos/Makefile
index 96300b6..06a68c0 100644
--- a/protos/Makefile
+++ b/protos/Makefile
@@ -19,7 +19,7 @@
 # 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, ext_config.proto and tech_profile.proto
-OPENOLT_PROTO_VER ?= v4.1.5
+OPENOLT_PROTO_VER ?= v4.2.0
 
 CXX ?= g++
 CPPFLAGS += `pkg-config --cflags protobuf grpc` -I googleapis/gens -I./