diff --git a/package.json b/package.json
index e8cf485..56d9008 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
   },
   "homepage": "https://github.com/unshiftio/querystringify",
   "devDependencies": {
-    "assume": "~1.5.0",
+    "assume": "~2.0.0",
     "istanbul": "0.4.x",
     "mocha": "~3.5.0",
     "pre-commit": "~1.2.0"