diff --git a/Makefile b/Makefile
index 6abcae2..70c5cc6 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,7 @@
 
 ## Variables
 OPENOLTDEVICE     ?= sim
-OPENOLT_PROTO_VER ?= v5.1.0
+OPENOLT_PROTO_VER ?= v5.2.1
 
 DOCKER                     ?= docker
 DOCKER_REGISTRY            ?=