diff --git a/Makefile b/Makefile
index 43f0f19..09e4fff 100644
--- a/Makefile
+++ b/Makefile
@@ -29,7 +29,7 @@
 
 ## Variables
 OPENOLTDEVICE     ?= sim
-OPENOLT_PROTO_VER ?= v5.6.5
+OPENOLT_PROTO_VER ?= v5.6.6
 
 DOCKER                     ?= docker
 DOCKER_REGISTRY            ?=