Index: xfce4-session-4.8.2/xfce4-session/xfsm-shutdown-helper.c
===================================================================
--- xfce4-session-4.8.2.orig/xfce4-session/xfsm-shutdown-helper.c
+++ xfce4-session-4.8.2/xfce4-session/xfsm-shutdown-helper.c
@@ -71,6 +71,8 @@
 
 #include <libxfce4util/libxfce4util.h>
 
+#include <xfconf/xfconf.h>
+
 #include "xfsm-shutdown-helper.h"
 #include "xfsm-global.h"
 
@@ -1722,6 +1724,24 @@ gboolean xfsm_shutdown_helper_send_passw
   return TRUE;
 }
 
+static void
+lock_screen (void)
+{
+  XfconfChannel *channel;
+  gboolean ret;
+  gint exit_status;
+
+  channel = xfconf_channel_get ("xfce4-power-manager");
+  if (xfconf_channel_get_bool (channel, "/xfce4-power-manager/lock-screen-suspend-hibernate", TRUE))
+    {
+      ret = g_spawn_command_line_sync ("xflock4", NULL, NULL, &exit_status, NULL);
+      if (!ret || exit_status != 0)
+        {
+          g_warning ("Could not lock screen");
+        }
+    }
+}
+
 /**
  * xfsm_shutdown_helper_shutdown:
  *
@@ -1785,6 +1805,8 @@ gboolean xfsm_shutdown_helper_suspend (X
 {
   g_return_val_if_fail (!error || !*error, FALSE);
 
+  lock_screen ();
+
 #ifdef ENABLE_UPOWER
   if ( helper->sleep_backend == XFSM_SLEEP_BACKEND_UPOWER )
     {
@@ -1812,6 +1834,8 @@ gboolean xfsm_shutdown_helper_hibernate
 {
   g_return_val_if_fail (!error || !*error, FALSE);
 
+  lock_screen ();
+
 #ifdef ENABLE_UPOWER
   if ( helper->sleep_backend == XFSM_SLEEP_BACKEND_UPOWER )
     {