diff --git a/Dockerfile b/Dockerfile
index 33de4ca..51e2a20 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,9 @@
 FROM registry.gitlab.com/thallian/docker-confd-env:master
 
-RUN apk add --no-cache postfix postfix-ldap spamassassin-client libstdc++ g++ make tar libmilter-dev
+RUN apk add --no-cache postfix postfix-ldap libressl spamassassin-client libstdc++ g++ make tar 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 --strip 1
+RUN wget -qO- https://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