diff --git a/sshbackup b/sshbackup
index 3abdb5d..7acdab7 100755
--- a/sshbackup
+++ b/sshbackup
@@ -69,8 +69,10 @@ preflight()
 {
 
     #amiroot?
-    if [ $(whoami) != "root" ]; then
-        echo "aborting mission. you must be root."
+    # Thhis is a safter way of testing this
+    # See: http://askubuntu.com/questions/30148/how-can-i-determine-whether-a-shellscript-runs-as-root-or-not/
+    if ! [ $(id -u) = 0 ]; then
+        echo "aborting mission, you must be root."
         return 1
     fi