diff --git a/tools/Dockerfile b/tools/Dockerfile
index 563868d0..abae662e 100644
--- a/tools/Dockerfile
+++ b/tools/Dockerfile
@@ -1,6 +1,7 @@
 FROM gliderlabs/alpine
 MAINTAINER Weaveworks Inc <help@weave.works>
 WORKDIR /home/weave
-RUN ["apk-install", "ethtool", "conntrack-tools", "curl", "iptables", "iproute2", "docker"]
+RUN ["apk", "add", "--update", "ethtool", "conntrack-tools", "curl", "iptables", "iproute2", "docker"]
+RUN ["sh", "-c", "rm -rf /var/cache/apk/*"]
 ADD ./weave /home/weave/
 ENTRYPOINT ["/home/weave/weave"]