diff --git a/javascript/package.json b/javascript/package.json
index 84d1eca..52dfbc1 100644
--- a/javascript/package.json
+++ b/javascript/package.json
@@ -14,7 +14,7 @@
   "devDependencies": {
     "babel-preset-es2015": "^6.13.2",
     "babel-register": "^6.11.6",
-    "chai": "^3.5.0",
+    "chai": "4.3.4",
     "chance": "^1.0.4",
     "mocha": "^3.0.2"
   }