diff --git a/Dockerfile b/Dockerfile
index ae073230..2475ab94 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -87,7 +87,7 @@ ENV VPNSP="private internet access" \
 ENTRYPOINT /entrypoint
 EXPOSE 8000/tcp 8888/tcp 8388/tcp 8388/udp
 HEALTHCHECK --interval=3m --timeout=3s --start-period=20s --retries=1 CMD /entrypoint healthcheck
-RUN apk add -q --progress --no-cache --update openvpn ca-certificates iptables unbound tinyproxy tzdata && \
+RUN apk add -q --progress --no-cache --update openvpn ca-certificates iptables ip6tables unbound tinyproxy tzdata && \
     echo "http://dl-cdn.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories && \
     apk add -q --progress --no-cache --update shadowsocks-libev && \
     rm -rf /var/cache/apk/* /etc/unbound/* /usr/sbin/unbound-* /etc/tinyproxy/tinyproxy.conf && \