diff --git a/Dockerfile b/Dockerfile
index ae5864e..6f11f17 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,8 +7,10 @@ ENV CFLAGS=-Ofast
 ENV BUILD_DEPS   curl make build-essential git libevent-dev libexpat1-dev autoconf file libssl-dev byacc
 ENV RUNTIME_DEPS bash util-linux coreutils findutils grep libssl1.1 ldnsutils libevent-2.1 expat ca-certificates runit runit-helper
 
-RUN apt-get update; apt-get -qy dist-upgrade; apt-get -qy clean
-RUN apt-get install -qy --no-install-recommends $RUNTIME_DEPS
+RUN apt-get update; apt-get -qy dist-upgrade; apt-get -qy clean && \
+    apt-get install -qy --no-install-recommends $RUNTIME_DEPS && \
+    rm -fr /tmp/* /var/tmp/* /var/cache/apt/* /var/lib/apt/lists/* /var/log/apt/* /var/log/*.log
+
 RUN update-ca-certificates 2> /dev/null || true
 
 ENV UNBOUND_GIT_URL https://github.com/jedisct1/unbound.git
@@ -16,7 +18,7 @@ ENV UNBOUND_GIT_REVISION 35ac577d99d56869f2f87dcc7b5e36b8996df5ca
 
 WORKDIR /tmp
 
-RUN apt-get install -qy --no-install-recommends $BUILD_DEPS && \
+RUN apt-get update; apt-get install -qy --no-install-recommends $BUILD_DEPS && \
     git clone --depth=1000 "$UNBOUND_GIT_URL" && \
     cd unbound && \
     git checkout "$UNBOUND_GIT_REVISION" && \