diff --git a/tools/server-remove-skel.sh b/tools/server-remove-skel.sh
index 0dc95dd..dd738d0 100755
--- a/tools/server-remove-skel.sh
+++ b/tools/server-remove-skel.sh
@@ -2,7 +2,7 @@
 
 # remove skeleton **files**
 
-if ! [ "$UID" = "0" ]; then
+if ! [ "$(id -u)" = "0" ]; then
     echo "not root"
     exit 1
 fi