http://bugs.gentoo.org/501370
http://bugzilla.xfce.org/show_bug.cgi?id=10679
--- a/scripts/xflock4+++ b/scripts/xflock4@@ -35,7 +35,8 @@# else run another access locking utility, if installed
for lock_cmd in \
"xlock -mode blank" \
- "slock"+ "slock" \+ "alock -bg blank -auth pam" do
set -- $lock_cmd
if command -v -- $1 >/dev/null 2>&1; then