diff --git a/Dockerfile b/Dockerfile
index 246ee71..c87f5d6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,7 @@
 FROM alpine:3.7
 LABEL maintainer="Sebastian Hugentobler <sebastian@vanwa.ch>"
 
-ENV S6_OVERLAY_VERSION=v1.21.2.2
+ENV S6_OVERLAY_VERSION=v1.21.4.0
 
 RUN apk --no-cache add libressl syslog-ng incron && \
     wget -qO- https://github.com/just-containers/s6-overlay/releases/download/$S6_OVERLAY_VERSION/s6-overlay-amd64.tar.gz | tar -xz -C / && \