Create a new property "/general/LockCommand" on channel "xfce4-session".

$ xflock4
Property "/general/LockCommand" does not exist on channel "xfce4-session".

---
 settings/xfce4-session.xml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/settings/xfce4-session.xml b/settings/xfce4-session.xml
index a200a37..a1c87bd 100644
--- a/settings/xfce4-session.xml
+++ b/settings/xfce4-session.xml
@@ -3,6 +3,7 @@
 <channel name="xfce4-session" version="1.0">
   <property name="general" type="empty">
     <property name="FailsafeSessionName" type="string" value="Failsafe"/>
+    <property name="LockCommand" type="string" value=""/>
   </property>
   <property name="sessions" type="empty">
     <property name="Failsafe" type="empty">
-- 
2.1.0