diff --git lib/agent/actions/lock/linux/prey-lock3 lib/agent/actions/lock/linux/prey-lock3
index 9377d219..08c0a88e 100755
--- lib/agent/actions/lock/linux/prey-lock3
+++ lib/agent/actions/lock/linux/prey-lock3
@@ -138,12 +138,12 @@ class Lock:
         self.window.set_resizable(False)
         self.window.fullscreen()
 
-        #_monitor = self.window.get_display().get_primary_monitor()
-        #main_screen_width = _monitor.get_geometry().width
-        #main_screen_height = _monitor.get_geometry().height
-        _monitor = Gdk.Screen.get_default()
-        main_screen_width = _monitor.get_width()
-        main_screen_height = _monitor.get_height()
+        _monitor = self.window.get_display().get_primary_monitor()
+        main_screen_width = _monitor.get_geometry().width
+        main_screen_height = _monitor.get_geometry().height
+        #_monitor = Gdk.Screen.get_default()
+        #main_screen_width = _monitor.get_width()
+        #main_screen_height = _monitor.get_height()
         main_screen_middle = main_screen_width / 2
 
         # print "Main screen size: %s x %s" % (main_screen_width, main_screen_height)
@@ -265,7 +265,16 @@ class Lock:
         self.window.show_all()
         # self.window.set_focus(self.entry)
         seat = self.window.get_display().get_default_seat()
-       
+        seat.grab(
+            fixed.get_parent_window(),
+            Gdk.SeatCapabilities.KEYBOARD,
+            True,
+            None,
+            None,
+            None,
+            None,
+            None,
+        )
         self.label.hide()