diff --git a/package.json b/package.json
index 6b668db..10b1e8d 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
   "devDependencies": {
     "eslint-config-xo-lukechilds": "^1.0.1",
     "nodemon": "^1.10.2",
-    "xo": "^0.19.0"
+    "xo": "^0.21.1"
   },
   "scripts": {
     "start": "node index.js",