diff --git a/ColorlampBase.js b/ColorlampBase.js
index f9ec149..e7d5e41 100644
--- a/ColorlampBase.js
+++ b/ColorlampBase.js
@@ -15,11 +15,11 @@ class HCColorlamp extends HCControlBase {
 	}
 
 	turnOn() {
-		return Promise.reject("Not implemented");
+		return Promise.reject(new Error("Not implemented"));
 	}
 
 	turnOff() {
-		return Promise.reject("Not implemented");
+		return Promise.reject(new Error("Not implemented"));
 	}
 
 	togglePower() {
@@ -31,7 +31,7 @@ class HCColorlamp extends HCControlBase {
 	}
 
 	setBrightness(brightness) {
-		return Promise.reject("Not implemented");
+		return Promise.reject(new Error("Not implemented"));
 	}
 
 	/**
@@ -43,11 +43,11 @@ class HCColorlamp extends HCControlBase {
 	 * @param {Number} color.l Lightness
 	 */
 	setColor(color) {
-		return Promise.reject("Not implemented");
+		return Promise.reject(new Error("Not implemented"));
 	}
 
 	setEffect(id) {
-		return Promise.reject("Not implemented");
+		return Promise.reject(new Error("Not implemented"));
 	}
 }
 
diff --git a/SwitchBase.js b/SwitchBase.js
index 5c153f3..9e7153b 100644
--- a/SwitchBase.js
+++ b/SwitchBase.js
@@ -11,11 +11,11 @@ class HCSwitchBase extends HCControlBase {
 	}
 
 	turnOn() {
-		return Promise.reject("Not implemented");
+		return Promise.reject(new Error("Not implemented"));
 	}
 
 	turnOff() {
-		return Promise.reject("Not implemented");
+		return Promise.reject(new Error("Not implemented"));
 	}
 
 	togglePower() {