diff --git a/lib/module.js b/lib/module.js
index 3f1964f..3eac197 100644
--- a/lib/module.js
+++ b/lib/module.js
@@ -67,7 +67,7 @@ function resolveContentType (type) {
 }
 
 async function createFeed (feedOptions, callback) {
-  if (['rss2', 'json1', 'atom1'].indexOf(feedOptions.type) === -1) {
+  if (!['rss2', 'json1', 'atom1'].includes(feedOptions.type)) {
     logger.fatal(`Could not create Feed ${feedOptions.path} - Unknown feed type`)
     return callback(null, '', feedOptions.cacheTime)
   }