diff --git a/installer/sudo-cmd.sh b/installer/sudo-cmd.sh
index c18962c..7849e92 100644
--- a/installer/sudo-cmd.sh
+++ b/installer/sudo-cmd.sh
@@ -1,5 +1,5 @@
 # Not every platform has or needs sudo, gotta save them O(1)s...
 sudo_cmd=""
 if [ type -p sudo ]; then
-  ((EUID)) && [[ -z "$ANDROID_ROOT" ]] && sudo_cmd="sudo"
+  ((EUID)) && [[ -z "${ANDROID_ROOT-}" ]] && sudo_cmd="sudo"
 fi