diff --git a/package.json b/package.json
index 8166c83..ab13be8 100644
--- a/package.json
+++ b/package.json
@@ -60,7 +60,7 @@
     "babel-register": "^6.3.13",
     "budo": "^10.0.0",
     "cz-conventional-changelog": "2.0.0",
-    "expect": "^1.13.4",
+    "expect": "^21.0.2",
     "mocha": "^3.2.0",
     "to-vfile": "^2.0.0",
     "uglify-js": "^3.0.27"