diff --git a/scripts/xflock4 b/scripts/xflock4
index 369ec33..a59d89b 100644
--- a/scripts/xflock4
+++ b/scripts/xflock4
@@ -19,11 +19,11 @@
 #  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 #
 
-if test x"`which xscreensaver-command 2>/dev/null`" != x""; then
+if ps aux | grep x[s]creensaver > /dev/null 2>&1; then
     xscreensaver-command -lock 
-elif test x"`which gnome-screensaver-command 2>/dev/null`" != x""; then
+elif ps aux | grep gnome-[s]creensaver > /dev/null 2>&1; then
     gnome-screensaver-command --lock
 else
-    xlock $*
+    xlock -mode blank $*
 fi
 exit 0