diff --git a/cleanup_image.sh b/cleanup_image.sh
index cd91612..8474aeb 100644
--- a/cleanup_image.sh
+++ b/cleanup_image.sh
@@ -26,12 +26,24 @@ if [[ -d "${mount}" ]]; then
         (cat /dev/zero >"${mount}/zero.fill" 2>/dev/null || true); sync; rm -f "${mount}/zero.fill"
     fi
 
-    umount "${mount}/dev/pts" || fuser -ckv "${mount}/dev/pts" || umount --force --lazy "${mount}/dev/pts" || true
-    umount "${mount}/dev" || fuser -ckv "${mount}/dev" || umount --force --lazy "${mount}/dev" || true
-    umount "${mount}/proc" || fuser -ckv "${mount}/proc" || umount --force --lazy "${mount}/proc" || true
-    umount "${mount}/sys" || fuser -ckv "${mount}/sys" || umount --force --lazy "${mount}/sys" || true
-    umount "${mount}/boot" || fuser -ckv "${mount}/boot" || umount --force --lazy "${mount}/boot" || true
-    umount "${mount}" || fuser -ckv "${mount}" || umount --force --lazy "${mount}" || true
+    for mp in "${mount}/dev/pts" "${mount}/dev" "${mount}/proc" "${mount}/sys" "${mount}/boot" "${mount}" ; do
+        mountpoint "${mp}" && {
+            retries=0
+            force=""
+            while ! umount ${force} "${mp}" ; do
+                retries=$((retries + 1))
+                if [ "${retries}" -ge 10 ]; then
+                    echo "Could not unmount ${mp} after ${retries} attempts, giving up."
+                    exit 1
+                fi
+                if [ "${retries}" -eq 5 ]; then
+                    force="--force"
+                fi
+                fuser -ckv "${mp}"
+                sleep 1
+            done
+        }
+    done
 
     if [[ "${optimize}x" == "x" || "${optimize}x" == "yesx" ]]; then
         rootfs_partnum=${rootpartition}