diff --git a/install.sh b/install.sh
index b83c70e..3815938 100755
--- a/install.sh
+++ b/install.sh
@@ -6,7 +6,7 @@
 # GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
 #
 # must be root
-if [ "$USER" != "root" ]; then
+if [ "${EUID}" -ne 0 ]; then
   echo "You must be root to run this installer."
   exit
 fi