diff --git a/lamp-xenial64-fpm/bootstrap.sh b/lamp-xenial64-fpm/bootstrap.sh
index 3a898b1..92bae48 100644
--- a/lamp-xenial64-fpm/bootstrap.sh
+++ b/lamp-xenial64-fpm/bootstrap.sh
@@ -97,7 +97,7 @@ if [ ! -f /usr/bin/php ]; then
 	    #sudo cp $DIRDATA/ChartDirector/chartdir.ini /etc/php5/mods-available/
 	    #sudo php5enmod chartdir
 	#fi
-    sudo usermod -a -G www-data $(whoami)
+    sudo usermod -a -G www-data "$(whoami)"
 fi
 
 # --- Composer