diff --git a/keymapper/daemon.py b/keymapper/daemon.py
index 84bd89d0..04ea0933 100644
--- a/keymapper/daemon.py
+++ b/keymapper/daemon.py
@@ -79,6 +79,10 @@ class Daemon:
                 <method name='stop_injecting'>
                     <arg type='s' name='device' direction='in'/>
                 </method>
+                <method name='is_injecting'>
+                    <arg type='s' name='device' direction='in'/>
+                    <arg type='b' name='response' direction='out'/>
+                </method>
                 <method name='start_injecting'>
                     <arg type='s' name='device' direction='in'/>
                     <arg type='s' name='preset' direction='in'/>
@@ -121,6 +125,11 @@ class Daemon:
             return
 
         self.injectors[device].stop_injecting()
+        del self.injectors[device]
+
+    def is_injecting(self, device):
+        """Is this device being mapped?"""
+        return device in self.injectors
 
     def start_injecting(self, device, preset):
         """Start injecting the preset for the device.
diff --git a/keymapper/gtk/window.py b/keymapper/gtk/window.py
index 4642dc6c..350fb7d8 100755
--- a/keymapper/gtk/window.py
+++ b/keymapper/gtk/window.py
@@ -241,9 +241,7 @@ class Window:
             CTX_APPLY,
             'Applied the system default'
         )
-        # restart reading because after injecting the device landscape
-        # changes a bit
-        keycode_reader.start_reading(self.selected_device)
+        GLib.timeout_add(10, self.show_device_mapping_status)
 
     def on_save_preset_clicked(self, button):
         """Save changes to a preset to the file system."""
@@ -301,6 +299,7 @@ class Window:
         # restart reading because after injecting the device landscape
         # changes a bit
         keycode_reader.start_reading(self.selected_device)
+        GLib.timeout_add(10, self.show_device_mapping_status)
 
     def on_preset_autoload_switch_activate(self, _, active):
         """Load the preset automatically next time the user logs in."""
@@ -326,9 +325,17 @@ class Window:
         self.selected_preset = None
 
         self.populate_presets()
-        GLib.idle_add(
-            lambda: keycode_reader.start_reading(self.selected_device)
-        )
+        GLib.idle_add(lambda: keycode_reader.start_reading(device))
+
+        self.show_device_mapping_status()
+
+    def show_device_mapping_status(self):
+        """Figure out if this device is currently under keymappers control."""
+        if self.dbus.is_injecting(self.selected_device):
+            logger.info('This device is currently mapped.')
+            self.get('apply_system_layout').set_opacity(1)
+        else:
+            self.get('apply_system_layout').set_opacity(0.4)
 
     def on_create_preset_clicked(self, _):
         """Create a new preset and select it."""
diff --git a/tests/testcases/test_daemon.py b/tests/testcases/test_daemon.py
index 045f4e75..d5b88776 100644
--- a/tests/testcases/test_daemon.py
+++ b/tests/testcases/test_daemon.py
@@ -79,25 +79,58 @@ class TestDaemon(unittest.TestCase):
         config.clear_config()
 
     def test_daemon(self):
-        keycode_from = 9
-        keycode_to = 100
+        keycode_from_1 = 9
+        keycode_to_1 = 100
+        keycode_from_2 = 12
+        keycode_to_2 = 100
 
-        custom_mapping.change(keycode_from, 'a')
+        custom_mapping.change(keycode_from_1, 'a')
+        custom_mapping.change(keycode_from_2, 'b')
         clear_system_mapping()
-        system_mapping['a'] = keycode_to
+        system_mapping['a'] = keycode_to_1
+        system_mapping['b'] = keycode_to_2
 
-        custom_mapping.save('device 2', 'foo')
-        config.set_autoload_preset('device 2', 'foo')
+        preset = 'foo'
+
+        custom_mapping.save('device 2', preset)
+        config.set_autoload_preset('device 2', preset)
 
         pending_events['device 2'] = [
-            Event(evdev.events.EV_KEY, keycode_from - 8, 0)
+            Event(evdev.events.EV_KEY, keycode_from_1 - 8, 0),
         ]
 
         self.daemon = Daemon()
+        # starts mapping right after creation
+
+        self.assertTrue(self.daemon.is_injecting('device 2'))
+        self.assertFalse(self.daemon.is_injecting('device 1'))
+
+        event = uinput_write_history_pipe[0].recv()
+        self.assertEqual(event.type, evdev.events.EV_KEY)
+        self.assertEqual(event.code, keycode_to_1 - 8)
+        self.assertEqual(event.value, 0)
+
+        self.daemon.stop_injecting('device 2')
+        self.assertFalse(self.daemon.is_injecting('device 2'))
+
+        pending_events['device 2'] = [
+            Event(evdev.events.EV_KEY, keycode_from_2 - 8, 1),
+            Event(evdev.events.EV_KEY, keycode_from_2 - 8, 0),
+        ]
+
+        time.sleep(0.2)
+        self.assertFalse(uinput_write_history_pipe[0].poll())
+
+        self.daemon.start_injecting('device 2', preset)
+
+        event = uinput_write_history_pipe[0].recv()
+        self.assertEqual(event.type, evdev.events.EV_KEY)
+        self.assertEqual(event.code, keycode_to_2 - 8)
+        self.assertEqual(event.value, 1)
 
         event = uinput_write_history_pipe[0].recv()
         self.assertEqual(event.type, evdev.events.EV_KEY)
-        self.assertEqual(event.code, keycode_to - 8)
+        self.assertEqual(event.code, keycode_to_2 - 8)
         self.assertEqual(event.value, 0)
 
 
diff --git a/tests/testcases/test_integration.py b/tests/testcases/test_integration.py
index 5d5ccb96..3955e1c0 100644
--- a/tests/testcases/test_integration.py
+++ b/tests/testcases/test_integration.py
@@ -112,6 +112,11 @@ class TestIntegration(unittest.TestCase):
     def get_rows(self):
         return self.window.get('key_list').get_children()
 
+    def test_show_device_mapping_status(self):
+        # this function may not return True, otherwise the timeout
+        # runs forever
+        self.assertFalse(self.window.show_device_mapping_status())
+
     def test_autoload(self):
         self.window.on_preset_autoload_switch_activate(None, False)
         self.assertFalse(config.is_autoloaded(