diff --git a/cfg/install.sh b/cfg/install.sh
index 6b61215..f25d116 100644
--- a/cfg/install.sh
+++ b/cfg/install.sh
@@ -4,7 +4,6 @@
 set -e
 
 NAME="aios"
-BACKUP="${NAME}back"
 TARBALL="aios-bootstrap.tar.gz"
 
 echo "=== aios installation ==="