diff --git a/README.md b/README.md
index ca2cf34..b33950c 100644
--- a/README.md
+++ b/README.md
@@ -305,6 +305,20 @@ await fastify.register(require('@fastify/swagger-ui', {
 
 To ensure that models are correctly rendered at the bottom of the Swagger UI page, it's important to define your schemas using $refs through [fastify.addSchema](https://fastify.dev/docs/latest/Reference/Validation-and-Serialization/#adding-a-shared-schema). Directly embedding JSON schemas within the schema property of your route definitions in Fastify may lead to them not being displayed in Swagger UI.
 
+#### validatorUrl
+
+[SwaggerUI](https://github.com/swagger-api/swagger-ui/) can automatically validate the given specification using an online validator.
+To enable this behavior you can pass the [`validatorUrl`](https://github.com/swagger-api/swagger-ui/blob/master/docs/usage/configuration.md) option
+to this plugin which will be forwarded to SwaggerUI.
+
+```js
+fastify.register('@fastify/swagger-ui', {
+  validatorUrl: 'https://validator.swagger.io/validator'
+})
+```
+
+Note that this behavior is disabled by default in `@fastify/swagger-ui`.
+
 <a name="license"></a>
 ## License
 
diff --git a/examples/dynamic-openapi.js b/examples/dynamic-openapi.js
index ef0c33c..614263c 100644
--- a/examples/dynamic-openapi.js
+++ b/examples/dynamic-openapi.js
@@ -25,7 +25,9 @@ fastify.register(require('@fastify/swagger'), {
   hideUntagged: true
 })
 
-fastify.register(require('../index'))
+fastify.register(require('../index'), {
+  validatorUrl: false
+})
 
 fastify.register(async function (fastify) {
   fastify.put('/some-route/:id', {
@@ -113,6 +115,6 @@ fastify.register(async function (fastify) {
   }, (req, reply) => { reply.send({ hello: `Hello ${req.body.hello}` }) })
 })
 
-fastify.listen({ port: 3000 }, err => {
+fastify.listen({ port: 3000, hostname: '0.0.0.0' }, err => {
   if (err) throw err
 })
diff --git a/lib/swagger-initializer.js b/lib/swagger-initializer.js
index 0bff3b2..9f4054b 100644
--- a/lib/swagger-initializer.js
+++ b/lib/swagger-initializer.js
@@ -24,7 +24,8 @@ function swaggerInitializer (opts) {
       plugins: [
         SwaggerUIBundle.plugins.DownloadUrl
       ],
-      layout: "StandaloneLayout"
+      layout: "StandaloneLayout",
+      validatorUrl: ${serialize(opts.validatorUrl)},
     }, config, {
       url: resolveUrl('./json').replace('static/json', 'json'),
       oauth2RedirectUrl: resolveUrl('./oauth2-redirect.html')