diff --git a/Dockerfile b/Dockerfile
index 68085d9..627c9f7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,10 +1,10 @@
 FROM thallian/confd-env:latest
 
-RUN	apk add --no-cache postfix postfix-ldap rsyslog spamassassin-client g++ make
+RUN	apk add --no-cache postfix postfix-ldap rsyslog spamassassin-client g++ make tar
 RUN apk add --no-cache --repository http://dl-3.alpinelinux.org/alpine/edge/testing/ --allow-untrusted libmilter-dev
 
 RUN mkdir /tmp/spamass-milter
-RUN wget -qO- http://download.savannah.gnu.org/releases/spamass-milt/spamass-milter-0.4.0.tar.gz | tar -xz -C /tmp/spamass-milter
+RUN wget -qO- http://download.savannah.gnu.org/releases/spamass-milt/spamass-milter-0.4.0.tar.gz | tar -xz -C /tmp/spamass-milter --strip 1
 WORKDIR /tmp/spamass-milter
 RUN ./configure && make && make install
 RUN rm -rf /tmp/spamass-milter
@@ -12,7 +12,7 @@ RUN rm -rf /tmp/spamass-milter
 RUN chown root /var/spool/postfix/
 RUN chown root /var/spool/postfix/pid
 
-RUN apk del g++ make
+RUN apk del g++ make tar
 
 EXPOSE 25 587