diff --git a/backup b/backup
index 111e562..51ae2c6 100755
--- a/backup
+++ b/backup
@@ -1,13 +1,13 @@
 #!/bin/bash
 
-if [ -z ${BACKUP_PATH+x} ]
+if [ ${BACKUP_PATH:+x} ]
 then
     echo "BACKUP_PATH set to ${BACKUP_PATH}"
-    backupDir = BACKUP_PATH
-    oldBackupDir = BACKUP_PATH + '.bak'
+    backupDir=BACKUP_PATH
+    oldBackupDir=BACKUP_PATH + '.bak'
 else
-    backupDir = ~/Dropbox/b2g/nexus4-backup
-    oldBackupDir = ~/Dropbox/b2g/nexus4-backup.bak
+    backupDir=~/Dropbox/b2g/nexus4-backup
+    oldBackupDir=~/Dropbox/b2g/nexus4-backup.bak
 fi
 
 adb shell stop b2g