diff --git a/README.md b/README.md
index b241243..cb2c660 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,8 @@
 npm i @fastify/cors
 ```
 
+TypeScript note: `@fastify/cors` does not add Fastify decorators, so registering it preserves the existing instance, request, and reply shapes.
+
 ### Compatibility
 
 | Plugin version | Fastify version |
diff --git a/package.json b/package.json
index 5553632..2663da2 100644
--- a/package.json
+++ b/package.json
@@ -63,7 +63,7 @@
     "c8": "^11.0.0",
     "cors": "^2.8.5",
     "eslint": "^9.17.0",
-    "fastify": "^5.0.0",
+    "fastify": "github:fastify/fastify#feat/typed-decorators",
     "neostandard": "^0.12.0",
     "tsd": "^0.33.0",
     "typescript": "~5.9.2"
diff --git a/types/index.test-d.ts b/types/index.test-d.ts
index 4040e66..262858a 100644
--- a/types/index.test-d.ts
+++ b/types/index.test-d.ts
@@ -11,7 +11,7 @@ import fastifyCors, {
 
 const app = fastify()
 
-app.register(fastifyCors)
+expectType<typeof app>(app.register(fastifyCors))
 
 app.register(fastifyCors, {
   origin: true,