diff --git a/prebuilt/common/bin/backuptool.sh b/prebuilt/common/bin/backuptool.sh
index b546b4e..8722de2 100755
--- a/prebuilt/common/bin/backuptool.sh
+++ b/prebuilt/common/bin/backuptool.sh
@@ -171,6 +171,7 @@
       mkdir -p $C
       preserve_addon_d
       run_stages pre-backup backup post-backup
+      umount_extra $all_V3_partitions
     fi
     unmount_system
   ;;
diff --git a/prebuilt/common/bin/backuptool_ab.sh b/prebuilt/common/bin/backuptool_ab.sh
index f90d31f..49766bd 100755
--- a/prebuilt/common/bin/backuptool_ab.sh
+++ b/prebuilt/common/bin/backuptool_ab.sh
@@ -181,6 +181,7 @@
       mkdir -p $C
       preserve_addon_d
       run_stages pre-backup backup post-backup
+      umount_extra $all_V3_partitions
     else
       cleanup
     fi