diff --git a/bin/switch_virt.sh b/bin/switch_virt.sh
index ae2173f..6cb259c 100755
--- a/bin/switch_virt.sh
+++ b/bin/switch_virt.sh
@@ -1,13 +1,28 @@
-#!/bin/sh
+#!/bin/bash
 
-if [ "$1" -eq "kvm" ] ; then
+if [ $# -lt 1 ] ; then
+  echo "Usage: $0 <kvm|vbox>" >&2
+  exit 1
+fi
+
+if [ `whoami` != "root" ] ; then
+  if which sudo >/dev/null 2>&1 ; then
+    sudo $0 $*
+    exit
+  fi
+  echo "Sorry, this requires root." >&2
+  exit 1
+fi
+
+if [ "$1" == "kvm" ] ; then
   /etc/init.d/virtualbox stop
   modprobe kvm
   modprobe kvm_intel
-elif [ "$1" -eq "vbox" ]  ; then
+elif [ "$1" == "vbox" ]  ; then
   rmmod kvm_intel
   rmmod kvm
   /etc/init.d/virtualbox start
 else
   echo 'WTF?' >&2
+  exit 1
 fi