diff --git a/lib/devices/capabilities/power.js b/lib/devices/capabilities/power.js
index 328de9e..27100fa 100644
--- a/lib/devices/capabilities/power.js
+++ b/lib/devices/capabilities/power.js
@@ -4,7 +4,7 @@ const { Thing, SwitchablePower } = require('abstract-things');
 
 module.exports = Thing.mixin(Parent => class extends Parent.with(SwitchablePower) {
 	propertyUpdated(key, value) {
-		if(key === 'power') {
+		if(key === 'power' && value !== undefined) {
 			this.updatePower(value);
 		}
 
diff --git a/lib/devices/gateway/plug.js b/lib/devices/gateway/plug.js
index f17a565..987842d 100644
--- a/lib/devices/gateway/plug.js
+++ b/lib/devices/gateway/plug.js
@@ -21,7 +21,7 @@ module.exports = class Plug extends SubDevice
 
 		this.defineProperty('status', {
 			name: 'power',
-			mapper: v => v === 'on'
+			mapper: v => (v === '') ? undefined : (v === 'on')
 		});
 
 		this.defineProperty('load_voltage', {