diff --git a/tools/osbuilder/rootfs-builder/rootfs.sh b/tools/osbuilder/rootfs-builder/rootfs.sh
index 4ec5429e9f..d490a2567f 100755
--- a/tools/osbuilder/rootfs-builder/rootfs.sh
+++ b/tools/osbuilder/rootfs-builder/rootfs.sh
@@ -700,6 +700,10 @@ EOF
 		       -e '/^\[Unit\]/a ConditionPathExists=\/dev\/ptp0' \
 		       -e 's/^ReadWritePaths=\(.\+\) \/var\/lib\/chrony \(.\+\)$/ReadWritePaths=\1 -\/var\/lib\/chrony \2/m' \
 		       ${chrony_systemd_service}
+		# Disable automatic directory creation
+		sed -i -e 's/^\(StateDirectory=\)/#\1/g' \
+		       -e 's/^\(LogsDirectory=\)/#\1/g' \
+		       ${chrony_systemd_service}
 	fi
 
 	AGENT_DIR="${ROOTFS_DIR}/usr/bin"
diff --git a/tools/osbuilder/rootfs-builder/ubuntu/Dockerfile.in b/tools/osbuilder/rootfs-builder/ubuntu/Dockerfile.in
index 16fa213eb8..9698eb5bc0 100644
--- a/tools/osbuilder/rootfs-builder/ubuntu/Dockerfile.in
+++ b/tools/osbuilder/rootfs-builder/ubuntu/Dockerfile.in
@@ -42,7 +42,7 @@ RUN apt-get update && \
     libclang-dev \
     make \
     makedev \
-    multistrap \
+    mmdebstrap \
     musl \
     musl-dev \
     musl-tools \
diff --git a/tools/osbuilder/rootfs-builder/ubuntu/rootfs_lib.sh b/tools/osbuilder/rootfs-builder/ubuntu/rootfs_lib.sh
index 5843ffa6c0..8d9745384f 100644
--- a/tools/osbuilder/rootfs-builder/ubuntu/rootfs_lib.sh
+++ b/tools/osbuilder/rootfs-builder/ubuntu/rootfs_lib.sh
@@ -4,43 +4,22 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-build_dbus() {
-	local rootfs_dir=$1
-	ln -sf /lib/systemd/system/dbus.service $rootfs_dir/etc/systemd/system/dbus.service
-	ln -sf /lib/systemd/system/dbus.socket $rootfs_dir/etc/systemd/system/dbus.socket
-}
-
 build_rootfs() {
 	local rootfs_dir=$1
-	local multistrap_conf=multistrap.conf
-
-	# For simplicity's sake, use multistrap for foreign and native bootstraps.
-	cat > "$multistrap_conf" << EOF
-[General]
-cleanup=true
-aptsources=Ubuntu
-bootstrap=Ubuntu
-
-[Ubuntu]
-source=$REPO_URL
-keyring=ubuntu-keyring
-suite=$OS_VERSION
-packages=$PACKAGES $EXTRA_PKGS
-EOF
 
 	# This fixes the spurious error
 	# E: Can't find a source to download version '2021.03.26' of 'ubuntu-keyring:amd64'
 	apt update
-
-	if ! multistrap -a "$DEB_ARCH" -d "$rootfs_dir" -f "$multistrap_conf"; then
-		if [ "$OS_VERSION" = "focal" ]; then
-			echo "WARN: multistrap failed, proceed with hack for Ubuntu 20.04"
-			build_dbus $rootfs_dir
-		else
-			echo "ERROR: multistrap failed, cannot proceed" && exit 1
-		fi
+	# focal version of mmdebstrap only supports comma separated package lists
+	if [ "$OS_VERSION" = "focal" ]; then
+		PACKAGES=$(echo "$PACKAGES" | tr ' ' ',')
+		EXTRA_PKGS=$(echo "$EXTRA_PKGS" | tr ' ' ',')
+	fi
+	if ! mmdebstrap --mode auto --arch "$DEB_ARCH" --variant required \
+			--include "$PACKAGES,$EXTRA_PKGS" "$OS_VERSION" "$rootfs_dir" "$REPO_URL"; then
+		echo "ERROR: mmdebstrap failed, cannot proceed" && exit 1
 	else
-		echo "INFO: multistrap succeeded"
+		echo "INFO: mmdebstrap succeeded"
 	fi
 	rm -rf "$rootfs_dir/var/run"
 	ln -s /run "$rootfs_dir/var/run"