diff --git a/Dockerfile b/Dockerfile
index e9b3428..78a6372 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 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 apk add --no-cache postfix postfix-ldap libressl syslog-ng spamassassin-client libstdc++ g++ make tar libmilter-dev
 
 RUN mkdir /tmp/spamass-milter
 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