diff --git a/docs/custom_vm.md b/docs/custom_vm.md
index c3d6ee6..9b0fcd4 100644
--- a/docs/custom_vm.md
+++ b/docs/custom_vm.md
@@ -40,6 +40,7 @@
 adb push debian.img.tar /data/local/tmp/
 adb shell tar xf /data/local/tmp/debian.img.tar -C /data/local/tmp/
 adb shell rm /data/local/tmp/debian.img.tar
+adb shell chmod a+w /data/local/tmp/debian.img
 rm debian.img.tar
 ```