diff --git a/package.json b/package.json
index f3cb0ac..669d447 100644
--- a/package.json
+++ b/package.json
@@ -60,7 +60,7 @@
     "@rollup/plugin-json": "^6.0.1",
     "@types/chai": "^4.3.8",
     "@types/mocha": "^10.0.2",
-    "chai": "^4.3.10",
+    "chai": "^5.0.0",
     "cross-env": "^7.0.3",
     "eslint": "^8.51.0",
     "eslint-config-preact": "^1.3.0",
@@ -78,7 +78,7 @@
     "npm-run-all2": "^6.0.0",
     "puppeteer": "^22.0.0",
     "rollup": "^4.0.0",
-    "sinon": "^16.1.0",
+    "sinon": "^18.0.0",
     "sinon-chai": "^3.7.0",
     "typescript": "^4.9.5"
   },