diff --git a/lib/spec/openapi/utils.js b/lib/spec/openapi/utils.js
index b3931a49..773fe930 100644
--- a/lib/spec/openapi/utils.js
+++ b/lib/spec/openapi/utils.js
@@ -82,7 +82,7 @@ function transformDefsToComponents (jsonSchema) {
   if (typeof jsonSchema === 'object' && jsonSchema !== null) {
     // Handle patternProperties, that is not part of OpenAPI definitions
     if (jsonSchema.patternProperties) {
-      jsonSchema.additionalProperties = Object.values(jsonSchema.patternProperties)[0];
+      jsonSchema.additionalProperties = Object.values(jsonSchema.patternProperties)[0]
       delete jsonSchema.patternProperties
     } else if (jsonSchema.const) {
       // OAS 3.1 supports `const` but it is not supported by `swagger-ui`
diff --git a/lib/util/common.js b/lib/util/common.js
index 4802a254..da592534 100644
--- a/lib/util/common.js
+++ b/lib/util/common.js
@@ -3,6 +3,7 @@
 const fs = require('fs')
 const path = require('path')
 const Ref = require('json-schema-resolver')
+const cloner = require('rfdc')({ proto: true, circles: false })
 const { rawRequired } = require('../symbols')
 const { xConsume } = require('../constants')
 
@@ -34,7 +35,7 @@ function addHook (fastify, pluginOptions) {
   return {
     routes,
     Ref () {
-      const externalSchemas = Array.from(sharedSchemasMap.values())
+      const externalSchemas = cloner(Array.from(sharedSchemasMap.values()))
       return Ref(Object.assign(
         { applicationUri: 'todo.com' },
         pluginOptions.refResolver,
diff --git a/package.json b/package.json
index c5e1bce9..370153e4 100644
--- a/package.json
+++ b/package.json
@@ -62,7 +62,8 @@
     "fastify-static": "^4.0.0",
     "js-yaml": "^4.0.0",
     "json-schema-resolver": "^1.3.0",
-    "openapi-types": "^10.0.0"
+    "openapi-types": "^10.0.0",
+    "rfdc": "^1.3.0"
   },
   "standard": {
     "ignore": [
diff --git a/test/spec/openapi/refs.js b/test/spec/openapi/refs.js
index 113474c5..c27ace70 100644
--- a/test/spec/openapi/refs.js
+++ b/test/spec/openapi/refs.js
@@ -135,6 +135,36 @@ test('support $ref in response schema', async (t) => {
   await Swagger.validate(openapiObject)
 })
 
+test('support $ref for enums in other schemas', async (t) => {
+  const fastify = Fastify()
+
+  const enumSchema = { $id: 'order', anyOf: [{ type: 'string', const: 'foo' }, { type: 'string', const: 'bar' }] }
+  const enumRef = { $ref: 'order' }
+  const objectWithEnumSchema = { $id: 'object', type: 'object', properties: { type: enumRef }, required: ['type'] }
+
+  await fastify.register(fastifySwagger, openapiOption)
+  await fastify.register(async (instance) => {
+    instance.addSchema(enumSchema)
+    instance.addSchema(objectWithEnumSchema)
+    instance.post('/', { schema: { body: { type: 'object', properties: { order: { $ref: 'order' } } } } }, async () => ({ result: 'OK' }))
+  })
+
+  await fastify.ready()
+
+  const responseBeforeSwagger = await fastify.inject({ method: 'POST', url: '/', payload: { order: 'foo' } })
+
+  t.equal(responseBeforeSwagger.statusCode, 200)
+  const openapiObject = fastify.swagger()
+
+  t.equal(typeof openapiObject, 'object')
+
+  await Swagger.validate(openapiObject)
+
+  const responseAfterSwagger = await fastify.inject({ method: 'POST', url: '/', payload: { order: 'foo' } })
+
+  t.equal(responseAfterSwagger.statusCode, 200)
+})
+
 test('support nested $ref schema : complex case without modifying buildLocalReference', async (t) => {
   const fastify = Fastify()
   fastify.register(fastifySwagger, { openapi: {} })