diff --git a/Dockerfile b/Dockerfile
index 3f6c2fe..d6f04bb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,6 +16,8 @@ RUN	echo "APT::Install-Recommends \"0\";\nAPT::Install-Suggests \"0\";" \
 RUN	apt-get install -y build-essential fakeroot devscripts
 # - cross-build tools
 RUN	apt-get install -y xdeb sbuild pdebuild-cross
+# - aufs tools for sbuild
+RUN	apt-get install -y aufs-tools
 # - git
 RUN	apt-get install -y git ca-certificates openssh-client
 # - reprepro
@@ -32,11 +34,6 @@ RUN	wget -O - -q http://archive.raspbian.org/raspbian.public.key | \
 	    apt-key --keyring /usr/share/keyrings/debian-archive-keyring.gpg \
 	        add -
 
-############################
-# Sbuild configuration:
-# - aufs on tmpfs config
-ADD	schroot-04tmpfs /etc/schroot/setup.d/04tmpfs
-
 ############################
 # Monkey patches
 #
diff --git a/local-config-example.sh b/local-config-example.sh
index a7f77ff..b6c4a92 100644
--- a/local-config-example.sh
+++ b/local-config-example.sh
@@ -23,6 +23,9 @@
 # Add repo to distro
 #DISTRO_REPOS[jessie]+=" dovetail-automata"
 
+# Use aufs on tmpfs in sbuild
+#SBUILD_USE_AUFS="true"
+
 # Use http/https proxy for package downloads. Especially useful for
 # caching packages between removing and rebuilding schroots.
 #
diff --git a/scripts/base-config.sh b/scripts/base-config.sh
index 6cfad3f..5146392 100644
--- a/scripts/base-config.sh
+++ b/scripts/base-config.sh
@@ -2,6 +2,9 @@
 # Default arch list
 ARCHES="amd64 i386 armhf"
 
+# Use aufs on tmpfs in sbuild
+SBUILD_USE_AUFS="false"
+
 
 ####################################
 # Docker configuration
diff --git a/scripts/docker.sh b/scripts/docker.sh
index 0dc1fd8..a6871b1 100644
--- a/scripts/docker.sh
+++ b/scripts/docker.sh
@@ -21,11 +21,7 @@ docker_set_user() {
 
 docker_build() {
     msg "Building Docker container image '$DOCKER_IMAGE' from 'Dockerfile'"
-    mkdir -p docker
-    cp $SCRIPTS_DIR/schroot-04tmpfs docker
-    cp Dockerfile docker
-    run docker build -t $DOCKER_IMAGE docker
-    rm -rf docker
+    run bash -c "docker build -t $DOCKER_IMAGE - < Dockerfile"
 }
 
 docker_run() {
diff --git a/scripts/sbuild.sh b/scripts/sbuild.sh
index d654a9d..8703a1a 100644
--- a/scripts/sbuild.sh
+++ b/scripts/sbuild.sh
@@ -95,10 +95,20 @@ sbuild_install_config() {
     local BUILD_ARCH=$(arch_build $DISTRO $HOST_ARCH)
     debug "    Installing schroot config:  $DISTRO-$BUILD_ARCH"
 
+    if $SBUILD_USE_AUFS; then
+	debug "    Installing aufs on tmpfs config"
+	run install -m 755 $SCRIPTS_DIR/schroot-04tmpfs \
+	    /etc/schroot/setup.d/04tmpfs
+	SCHROOT_UNION_TYPE="aufs"
+    else
+	SCHROOT_UNION_TYPE="none"
+    fi
+
     run bash -c "sed $SCRIPTS_DIR/schroot.conf \\
 	-e 's/@DISTRO@/$DISTRO/g' \\
 	-e 's/@BUILD_ARCH@/$BUILD_ARCH/g' \\
 	-e 's/@SCHROOT_PERSONALITY@/$SCHROOT_PERSONALITY/g' \\
+	-e 's/@SCHROOT_UNION_TYPE@/$SCHROOT_UNION_TYPE/g' \\
 	> /etc/schroot/chroot.d/$SBUILD_CHROOT"
 
     debug "      Contents of /etc/schroot/chroot.d/$SBUILD_CHROOT:"
diff --git a/scripts/schroot-04tmpfs b/scripts/schroot-04tmpfs
index 0abb856..c3f17c0 100755
--- a/scripts/schroot-04tmpfs
+++ b/scripts/schroot-04tmpfs
@@ -5,16 +5,10 @@
 #
 # Copied into /etc/schroot/setup.d/04tmpfs
 
-. "$SETUP_DATA_DIR/common-data"
-. "$SETUP_DATA_DIR/common-functions"
-. "$SETUP_DATA_DIR/common-config"
-
+. "$SETUP_DATA_DIR/common-data"  # $STAGE
+OVERLAY=/var/lib/schroot/union/overlay
 
 case $STAGE in
-    setup-start|setup-recover)
-	mount -t tmpfs overlay /var/lib/schroot/union/overlay
-	;;
-    setup-stop)
-	mount -t tmpfs overlay /var/lib/schroot/union/overlay
-	;;
+    setup-start|setup-recover) mount -t tmpfs overlay $OVERLAY ;;
+    setup-stop) umount -f $OVERLAY ;;
 esac
diff --git a/scripts/schroot.conf b/scripts/schroot.conf
index 8a99ff6..1165ab0 100644
--- a/scripts/schroot.conf
+++ b/scripts/schroot.conf
@@ -6,3 +6,4 @@ groups=root,sbuild
 root-groups=root,sbuild
 profile=sbuild
 personality=@SCHROOT_PERSONALITY@
+union-type=@SCHROOT_UNION_TYPE@