diff --git a/packages/core/package.json b/packages/core/package.json
index e6c74bd..aac1603 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -17,7 +17,7 @@
     "@flow/shared": "workspace:*"
   },
   "devDependencies": {
-    "@cloudflare/workers-types": "^4.20250712.0",
+    "@cloudflare/workers-types": "^5.20260727.1",
     "typescript": "^5.7.2",
     "vitest": "^3.2.7"
   }