diff --git a/Dockerfile b/Dockerfile
index 2ad2783..8752a94 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@ ADD rootfs.tar.xz /
 MAINTAINER sparklyballs
 
 # set version for s6 overlay
-ARG OVERLAY_VERSION="v1.19.1.1"
+ARG OVERLAY_VERSION="v1.21.2.2"
 ARG OVERLAY_ARCH="amd64"
 
 # environment variables