diff --git a/builder.go b/builder.go
index 11edf44..942b7df 100644
--- a/builder.go
+++ b/builder.go
@@ -284,7 +284,7 @@ func (b *builder) mountImg(ctx context.Context) error {
 	r := ctx.Value("release").(OSRelease)
 	if r.ID == ReleaseUbuntu {
 		if strings.HasPrefix(r.VersionID, "12.") {
-			mkfsExt4Opts = append(mkfsExt4Opts, "-O", "^has_journal")
+			mkfsExt4Opts = append(mkfsExt4Opts, "-O", "^has_journal,^metadata_csum")
 		}
 	}
 	logrus.Infof("mounting raw image")
diff --git a/templates/ubuntu12.Dockerfile b/templates/ubuntu12.Dockerfile
index dea0aa9..528fce4 100644
--- a/templates/ubuntu12.Dockerfile
+++ b/templates/ubuntu12.Dockerfile
@@ -2,6 +2,12 @@ FROM {{ .Image }}
 
 USER root
 
+# restore initctl
+RUN rm /sbin/initctl && dpkg-divert --rename --remove /sbin/initctl
+
+# setup ttyS0
+RUN cp /etc/init/tty1.conf /etc/init/ttyS0.conf && sed -i s/tty1/ttyS0/g /etc/init/ttyS0.conf
+
 RUN ARCH="$([ "$(uname -m)" = "x86_64" ] && echo amd64 || echo arm64)"; \
   apt-get update && \
   DEBIAN_FRONTEND=noninteractive apt-get -y install --no-install-recommends \