diff --git a/package.json b/package.json
index 4baacada..2117ab59 100644
--- a/package.json
+++ b/package.json
@@ -57,7 +57,7 @@
     "ts-jest": "27.0.5",
     "ts-node": "10.2.1",
     "typedoc": "0.21.6",
-    "typescript": "4.3.5"
+    "typescript": "5.9.3"
   },
   "dependencies": {
     "@stencila/logga": "^4.0.0",