diff --git a/package.json b/package.json
index 9989d0e..74c60f4 100644
--- a/package.json
+++ b/package.json
@@ -45,7 +45,7 @@
     "tz-parser": "3.1.3"
   },
   "devDependencies": {
-    "chai": "4.3.6",
+    "chai": "5.1.0",
     "eslint": "4.19.1",
     "eslint-config-standard": "11.0.0",
     "eslint-plugin-import": "2.25.4",