diff --git a/lib/controller.js b/lib/controller.js
index 559e5bea..8ece19ff 100644
--- a/lib/controller.js
+++ b/lib/controller.js
@@ -14,6 +14,8 @@ const mqttDevicePrefixRegex = new RegExp(`${settings.get().mqtt.base_topic}/[\\w
 const pollInterval = 60 * 1000; // seconds * 1000.
 const softResetTimeout = 3600 * 1000; // seconds * 1000.
 
+const allowedLogLevels = ['error', 'warn', 'info', 'debug'];
+
 /**
  * Home Assistant requires ALL attributes to be present in ALL MQTT messages send by the device.
  * https://community.home-assistant.io/t/missing-value-with-mqtt-only-last-data-set-is-shown/47070/9
@@ -340,11 +342,11 @@ class Controller {
         if (option === 'permit_join') {
             this.zigbee.permitJoin(message.toString().toLowerCase() === 'true');
         } else if (option === 'log_level') {
-            let level = message.toString().toLowerCase();
-            if (['error', 'warn', 'info', 'debug'].indexOf(level) > -1) {
+            const level = message.toString().toLowerCase();
+            if (allowedLogLevels.includes(level)) {
                 logger.warn(`Switching log level to '${level}'`);
-                logger.transports.console.level = message.toString().toLowerCase();
-                logger.transports.file.level = message.toString().toLowerCase();
+                logger.transports.console.level = level;
+                logger.transports.file.level = level;
             } else {
                 logger.error(`Could not set log level to '${level}'`);
             }