diff --git a/package.json b/package.json
index dc0af20..3a11412 100644
--- a/package.json
+++ b/package.json
@@ -32,7 +32,7 @@
     "url": "https://github.com/unshiftio/millisecond/issues"
   },
   "devDependencies": {
-    "assume": "~2.0.0",
+    "assume": "~2.2.0",
     "istanbul": "0.4.x",
     "mocha": "~3.5.0",
     "pre-commit": "~1.2.0",