diff --git a/Dockerfile b/Dockerfile
index 4653348..514a655 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,6 @@
 FROM dovecot/dovecot:latest
 
 RUN userdel _apt
+RUN groupdel ssl-cert
+RUN groupadd -r -g 101 postfix
 RUN useradd -u 100 -r -g 101 -d /var/spool/postfix -s /sbin/nologin -c "postfix" postfix