diff --git a/.changeset/sweet-insects-attack.md b/.changeset/sweet-insects-attack.md
new file mode 100644
index 00000000..767550f2
--- /dev/null
+++ b/.changeset/sweet-insects-attack.md
@@ -0,0 +1,5 @@
+---
+'@hono/zod-openapi': minor
+---
+
+feat(zod-openapi): make `app.openAPIRegistry` public
diff --git a/packages/zod-openapi/README.md b/packages/zod-openapi/README.md
index 902f3560..0b8d0fdd 100644
--- a/packages/zod-openapi/README.md
+++ b/packages/zod-openapi/README.md
@@ -174,6 +174,14 @@ app.openapi(
 )
 ```
 
+### The Registry
+
+You can access the [`OpenAPIRegistry`](https://github.com/asteasolutions/zod-to-openapi#the-registry) object via `app.openAPIRegistry`:
+
+```ts
+const registry = app.openAPIRegistry
+```
+
 ### Middleware
 
 Zod OpenAPI Hono is an extension of Hono, so you can use Hono's middleware in the same way:
diff --git a/packages/zod-openapi/src/index.ts b/packages/zod-openapi/src/index.ts
index e51a721a..9143dbf1 100644
--- a/packages/zod-openapi/src/index.ts
+++ b/packages/zod-openapi/src/index.ts
@@ -150,11 +150,11 @@ export class OpenAPIHono<
   S extends Schema = {},
   BasePath extends string = '/'
 > extends Hono<E, S, BasePath> {
-  #registry: OpenAPIRegistry
+  openAPIRegistry: OpenAPIRegistry
 
   constructor() {
     super()
-    this.#registry = new OpenAPIRegistry()
+    this.openAPIRegistry = new OpenAPIRegistry()
   }
 
   openapi = <
@@ -171,7 +171,7 @@ export class OpenAPIHono<
     handler: Handler<E, P, I, HandlerResponse<OutputType<R>>>,
     hook?: Hook<I, E, P, OutputType<R>>
   ): Hono<E, ToSchema<R['method'], P, I['in'], OutputType<R>>, BasePath> => {
-    this.#registry.registerPath(route)
+    this.openAPIRegistry.registerPath(route)
 
     const validators: MiddlewareHandler[] = []
 
@@ -224,7 +224,7 @@ export class OpenAPIHono<
   }
 
   getOpenAPIDocument = (config: OpenAPIObjectConfig) => {
-    const generator = new OpenApiGeneratorV3(this.#registry.definitions)
+    const generator = new OpenApiGeneratorV3(this.openAPIRegistry.definitions)
     const document = generator.generateDocument(config)
     return document
   }