diff --git a/meta/classes/image-container-extension.bbclass b/meta/classes/image-container-extension.bbclass
index e26604a..762be4a 100644
--- a/meta/classes/image-container-extension.bbclass
+++ b/meta/classes/image-container-extension.bbclass
@@ -19,6 +19,7 @@ containerize_rootfs() {
     # prepare OCI container image skeleton
     bbdebug 1 "prepare OCI container image skeleton"
     rm -rf "${oci_img_dir}"
+
     sudo umoci init --layout "${oci_img_dir}"
     sudo umoci new --image "${oci_img_dir}:${empty_tag}"
     sudo umoci config --image "${oci_img_dir}:${empty_tag}" \
@@ -27,7 +28,7 @@ containerize_rootfs() {
         "${oci_img_dir}_unpacked"
 
     # add root filesystem as the flesh of the skeleton
-    sudo cp -a "${rootfs}"/* "${oci_img_dir}_unpacked/rootfs/"
+    sudo sh -c "tar --one-file-system -C \"${rootfs}\" -cpf - . | tar -C \"${oci_img_dir}_unpacked/rootfs\" --strip-components=1 -xpf -"
     # clean-up temporary files
     sudo find "${oci_img_dir}_unpacked/rootfs/tmp" -mindepth 1 -delete
 
diff --git a/meta/classes/image-sdk-extension.bbclass b/meta/classes/image-sdk-extension.bbclass
index 426b925..2cc5933 100644
--- a/meta/classes/image-sdk-extension.bbclass
+++ b/meta/classes/image-sdk-extension.bbclass
@@ -33,15 +33,11 @@ do_populate_sdk() {
         sudo rm -f ${SDKCHROOT_DIR}/etc/apt/sources.list.d/isar-apt.list
     fi
 
-    sudo umount -R ${SDKCHROOT_DIR}/dev || true
-    sudo umount ${SDKCHROOT_DIR}/proc || true
-    sudo umount -R ${SDKCHROOT_DIR}/sys || true
-
     # Remove setup scripts
     sudo rm -f ${SDKCHROOT_DIR}/chroot-setup.sh ${SDKCHROOT_DIR}/configscript.sh
 
     # Make all links relative
-    for link in $(find ${SDKCHROOT_DIR}/ -type l); do
+    for link in $(find ${SDKCHROOT_DIR}/ -type l -xdev); do
         target=$(readlink $link)
 
         if [ "${target#/}" != "${target}" ]; then