diff --git a/Makefile b/Makefile
index c95af8d..ccb9d5c 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,7 @@
 
 ## Variables
 OPENOLTDEVICE     ?= asfvolt16
-OPENOLT_PROTO_VER ?= v3.3.6
+OPENOLT_PROTO_VER ?= v3.3.9
 GTEST_VER         ?= release-1.8.0
 CMOCK_VER         ?= 0207b30
 GMOCK_GLOBAL_VER  ?= 1.0.2