diff -Nru unity-greeter-14.04.10/src/settings-daemon.vala unity-greeter-14.04.10/src/settings-daemon.vala
--- unity-greeter-14.04.10/src/settings-daemon.vala	2014-04-07 21:36:56.000000000 -0700
+++ unity-greeter-14.04.10/src/settings-daemon.vala	2014-12-22 11:05:22.000000000 -0800
@@ -200,6 +200,23 @@
         }
     }
 
+    private void _set_idle_hint (bool idle_hint)
+    {
+        try
+        {
+            string session_id = Environment.get_variable("XDG_SESSION_ID");
+            string session_object = "/org/freedesktop/login1/session/%s".printf(session_id);
+            LogindSession session = Bus.get_proxy_sync (BusType.SYSTEM,
+                    "org.freedesktop.login1",
+                    session_object);
+            session.set_idle_hint (idle_hint);
+        }
+        catch (Error e)
+        {
+            warning ("Failed to set session idle hint: %s", e.message);
+        }
+    }
+
     public void set_active (bool value)
     {
         if (_active == value)
@@ -211,6 +228,7 @@
             debug ("Screensaver disabled");
 
         _set_active (value);
+        _set_idle_hint (value);
         active_changed (value);
     }
 
@@ -232,3 +250,9 @@
     public string session_name { get { return "ubuntu"; } }
     public uint32 inhibited_actions { get { return 0; } }
 }
+
+[DBus (name="org.freedesktop.login1.Session")]
+interface LogindSession : Object
+{
+    public abstract void set_idle_hint (bool idle_hint) throws IOError;
+}