diff --git a/examples/storage/redis/image/Dockerfile b/examples/storage/redis/image/Dockerfile
index 2247af5307..9f619a5ade 100644
--- a/examples/storage/redis/image/Dockerfile
+++ b/examples/storage/redis/image/Dockerfile
@@ -14,7 +14,7 @@
 
 FROM alpine:3.4
 
-RUN apk add -U redis sed bash && rm -rf /var/cache/apk/*
+RUN apk add --no-cache redis sed bash
 
 COPY redis-master.conf /redis-master/redis.conf
 COPY redis-slave.conf /redis-slave/redis.conf
diff --git a/test/images/dnsutils/Dockerfile b/test/images/dnsutils/Dockerfile
index 0689ef0a76..2d037e9f84 100644
--- a/test/images/dnsutils/Dockerfile
+++ b/test/images/dnsutils/Dockerfile
@@ -14,5 +14,4 @@
 
 FROM alpine
 
-RUN apk update --no-cache
-RUN apk add bind-tools
+RUN apk add --no-cache bind-tools