diff --git a/Dockerfile b/Dockerfile
index cf7bd85..7fe1c09 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-ARG P2POOL_BRANCH=v4.9
+ARG P2POOL_BRANCH=v4.9.1
 
 # Select latest Ubuntu LTS for the build image base
 FROM ubuntu:latest as build