diff --git a/Dockerfile b/Dockerfile
index f07b2ee..e9b3428 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,7 @@ FROM quay.io/thallian/confd-env:latest
 RUN apk add --no-cache postfix postfix-ldap syslog-ng 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