diff --git a/Dockerfile b/Dockerfile
index 1d51876..56b4309 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-ARG P2POOL_BRANCH=v3.8
+ARG P2POOL_BRANCH=v3.9
 
 # Select latest Ubuntu LTS for the build image base
 FROM ubuntu:latest as build