diff --git a/README.md b/README.md
index 9958b64..6047f98 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,7 @@ This package is responsible for compiling the application's `response` JSON sche
 |                                    v1.x |                  v3.x |                ^3.x |
 |                                    v2.x |                  v3.x |                ^4.x |
 |                                    v3.x |                  v4.x |                ^4.x |
+|                                    v3.x |                  v5.x |                ^4.x |
 
 ### fast-json-stringify Configuration
 
diff --git a/index.js b/index.js
index 2f14dd0..836b4c7 100644
--- a/index.js
+++ b/index.js
@@ -10,6 +10,10 @@ function SerializerSelector () {
 }
 
 function responseSchemaCompiler (fjsOpts, { schema /* method, url, httpStatus */ }) {
+  if (fjsOpts.schema && schema.$id && fjsOpts.schema[schema.$id]) {
+    fjsOpts.schema = { ...fjsOpts.schema }
+    delete fjsOpts.schema[schema.$id]
+  }
   return fastJsonStringify(schema, fjsOpts)
 }
 
diff --git a/package.json b/package.json
index 0fd96d6..d52874a 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@fastify/fast-json-stringify-compiler",
   "description": "Build and manage the fast-json-stringify instances for the fastify framework",
-  "version": "3.0.1",
+  "version": "4.0.0",
   "main": "index.js",
   "types": "index.d.ts",
   "scripts": {
@@ -25,10 +25,10 @@
     "fastify": "^4.0.0",
     "standard": "^17.0.0",
     "tap": "^16.0.0",
-    "tsd": "^0.20.0"
+    "tsd": "^0.21.0"
   },
   "dependencies": {
-    "fast-json-stringify": "^4.2.0"
+    "fast-json-stringify": "^5.0.0"
   },
   "tsd": {
     "directory": "test/types"
diff --git a/test/duplicate-schema.test.js b/test/duplicate-schema.test.js
new file mode 100644
index 0000000..d6904ed
--- /dev/null
+++ b/test/duplicate-schema.test.js
@@ -0,0 +1,26 @@
+'use strict'
+
+const t = require('tap')
+const FjsCompiler = require('../index')
+
+t.test('Use input schema duplicate in the externalSchemas', async t => {
+  t.plan(1)
+  const externalSchemas = {
+    schema1: {
+      $id: 'schema1',
+      type: 'number'
+    },
+    schema2: {
+      $id: 'schema2',
+      type: 'string'
+    }
+  }
+
+  const factory = FjsCompiler()
+  const compiler = factory(externalSchemas)
+
+  compiler({ schema: externalSchemas.schema1 })
+  compiler({ schema: externalSchemas.schema2 })
+
+  t.pass()
+})