diff --git a/README.md b/README.md
index c51dc0d..63ab525 100644
--- a/README.md
+++ b/README.md
@@ -176,11 +176,19 @@ app.register(require('fastify-overview'), {
   exposeRouteOptions: {
     method: 'POST', // default: 'GET'
     url: '/customUrl', // default: '/json-overview'
-  },
-   onRouteDefinition: (opts) => {
+  }, 
+  onRouteDefinition: (opts) => {
     return {
       schema: opts.schema
     }
+  }, 
+  onDecorateDefinition: (decoratorType, decoratorName, decoratorValue) => {
+     if (value && typeof value === 'object' && !Array.isArray(value)) {
+        return {
+           staticData: true
+        }
+     }
+     return { utilityFunction: true }
   }
 })
 
@@ -318,6 +326,37 @@ override the `source` property.
 ```
 In this example, the `url` property is overridden and the `url` length is returned instead of the `url`.
 
+### onDecorateDefinition
+
+Similar to `onRouteDefinition`, this option allows you to control which information about decorators is included in the overview.
+The passed function is called for `instance`, `request` and `reply` decorators but the decorator type is passed to the function as parameter.
+The default properties `name` and `type` can also be overwritten here. See the table below for an overview of exactly 
+how the function `onDecorateDefinition(decoratorType, decoratorName, decoratorValue)` is called for the different decorators.
+
+|                 Decorator                 | decoratorType   | decoratorName | decoratorValue    |
+|:-----------------------------------------:|-----------------|---------------|-------------------|
+| `app.decorate('db', {query: () => {}})`   | decorate        | db            | {query: () => {}} |
+| `app.decorateRequest('verify', () => {})` | decorateRequest | verify        | () => {}          |
+| `app.decorateReply('num', 42)`            | decorateReply   | num           | 42                |
+
+As an example, the function below returns the nested properties for object values.
+```js
+onDecorateDefinition: (type, name, value) => {
+   if (value && typeof value === 'object' && !Array.isArray(value)) {
+      return {
+         recursive: Object.entries(value).map(([key, val]) => {
+            return {
+               name: key,
+               type: Array.isArray(val) ? 'array' : typeof val
+            }
+         })
+      }
+   } else {
+      return {}
+   }
+}
+```
+
 ## License
 
 Copyright [Manuel Spigolon](https://github.com/Eomm), Licensed under [MIT](./LICENSE).
diff --git a/index.d.ts b/index.d.ts
index e16fce9..f8d6a61 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -50,15 +50,23 @@ interface RouteItem {
   source?: OverviewStructureSource,
 }
 
-export interface OverviewStructure<T = {}> {
+export interface Decorators {
+  instance?: Record<string, unknown>
+  request?: Record<string, unknown>
+  reply?: Record<string, unknown>
+}
+
+type ExtractDecoratorType<T extends Record<PropertyKey, unknown>, K extends keyof Decorators> = T extends Decorators ? T[K] : T
+
+export interface OverviewStructure<T = {}, D extends Record<PropertyKey, unknown> = {}> {
   id: Number,
   name: string,
   source?: OverviewStructureSource,
   children?: OverviewStructure<T>[],
   decorators?: {
-    decorate: OverviewStructureDecorator[],
-    decorateRequest: OverviewStructureDecorator[],
-    decorateReply: OverviewStructureDecorator[]
+    decorate: (Omit<OverviewStructureDecorator, keyof ExtractDecoratorType<D, 'instance'>> & ExtractDecoratorType<D, 'instance'>)[],
+    decorateRequest: (Omit<OverviewStructureDecorator, keyof ExtractDecoratorType<D, 'request'>> & ExtractDecoratorType<D, 'request'>)[],
+    decorateReply: (Omit<OverviewStructureDecorator, keyof ExtractDecoratorType<D, 'reply'>> & ExtractDecoratorType<D, 'reply'>)[]
   },
   hooks?: OverviewStructureHooks,
   routes?: (Omit<RouteItem, keyof T> & T)[]
@@ -87,6 +95,11 @@ export interface FastifyOverviewOptions {
    * Customise which properties of the route options will be included in the overview
    */
   onRouteDefinition?: (routeOptions: RouteOptions & { routePath: string; path: string; prefix: string }) => Record<string, unknown>
+
+  /**
+   * Customise which information from decorators should be added to the overview
+   */
+  onDecorateDefinition?: (type: 'decorate' | 'decorateRequest' | 'decorateReply', name: string, value: unknown) => Record<string, unknown>
 }
 
 export interface FastifyOverviewDecoratorOptions {
@@ -103,7 +116,7 @@ export interface FastifyOverviewDecoratorOptions {
 
 declare module 'fastify' {
   export interface FastifyInstance {
-    overview: <T = {}>(opts?: FastifyOverviewDecoratorOptions) => OverviewStructure<T>;
+    overview: <T = {}, D extends Record<PropertyKey, unknown> = {}>(opts?: FastifyOverviewDecoratorOptions) => OverviewStructure<T, D>;
   }
 }
 
diff --git a/index.js b/index.js
index 536aab1..c1c4596 100644
--- a/index.js
+++ b/index.js
@@ -167,10 +167,10 @@ function wrapFastify (instance, pluginOpts) {
   }
 }
 
-function wrapDecorator (instance, type, { addSource }) {
+function wrapDecorator (instance, type, { addSource, onDecorateDefinition }) {
   const originalDecorate = instance[type]
   instance[type] = function wrapDecorate (name, value) {
-    const decoratorNode = getDecoratorNode(name, value)
+    const decoratorNode = Object.assign(getDecoratorNode(name, value), onDecorateDefinition?.(type, name, value))
     if (addSource) {
       decoratorNode.source = getSource()[0]
     }
diff --git a/test/decorator.test.js b/test/decorator.test.js
index bb92b1b..dd658aa 100644
--- a/test/decorator.test.js
+++ b/test/decorator.test.js
@@ -63,3 +63,56 @@ test('decorator', async t => {
   t.same(reg3.decorators.decorateRequest, [{ name: 'sub-object', type: 'object' }])
   t.same(reg3.decorators.decorateReply, [{ name: 'sub', type: 'number' }])
 })
+
+test('onDecorateDefinition', async t => {
+  const app = fastify()
+  await app.register(plugin, {
+    onDecorateDefinition: (type, name, value) => {
+      if (value && typeof value === 'object' && !Array.isArray(value)) {
+        return {
+          recursive: Object.entries(value).map(([key, val]) => {
+            return {
+              name: key,
+              type: Array.isArray(val) ? 'array' : typeof val
+            }
+          })
+        }
+      } else {
+        return {}
+      }
+    }
+  })
+
+  app.decorate('emptyObj', {})
+  app.decorate('obj1', {
+    run: () => {}
+  })
+  app.decorateRequest('emptyObj', {})
+  app.decorateReply('obj2', {
+    test: 'str'
+  })
+
+  app.register(async function child1 (instance) {
+    instance.decorate('encapsulatedObj', {
+      a: () => {},
+      b: 'str',
+      c: false,
+      d: 42
+    })
+  })
+
+  await app.ready()
+
+  const root = app.overview()
+
+  t.equal(root.children.length, 1)
+  t.same(root.decorators.decorate, [{ name: 'emptyObj', type: 'object', recursive: [] }, { name: 'obj1', type: 'object', recursive: [{ name: 'run', type: 'function' }] }])
+  t.same(root.decorators.decorateReply, [{ name: 'obj2', type: 'object', recursive: [{ name: 'test', type: 'string' }] }])
+  t.same(root.decorators.decorateRequest, [{ name: 'emptyObj', type: 'object', recursive: [] }])
+
+  t.equal(root.children[0].name, 'child1')
+  const child1 = root.children[0]
+  t.same(child1.decorators.decorate, [{ name: 'encapsulatedObj', type: 'object', recursive: [{ name: 'a', type: 'function' }, { name: 'b', type: 'string' }, { name: 'c', type: 'boolean' }, { name: 'd', type: 'number' }] }])
+  t.equal(child1.decorators.decorateRequest.length, 0)
+  t.equal(child1.decorators.decorateReply.length, 0)
+})
diff --git a/test/types/index.test-d.ts b/test/types/index.test-d.ts
index 13de188..9a2179b 100644
--- a/test/types/index.test-d.ts
+++ b/test/types/index.test-d.ts
@@ -1,4 +1,4 @@
-import { expectType } from 'tsd'
+import { expectAssignable, expectError, expectType } from 'tsd'
 
 import fastify, { HTTPMethods } from 'fastify'
 import fastifyOverview, { OverviewStructure } from '../../index'
@@ -49,3 +49,64 @@ app
     expectType<number>(data.routes![0].url)
   })
   .ready()
+
+app
+  .register(fastifyOverview, {
+    onDecorateDefinition: (type, name, value) => {
+      if (typeof value === 'object' && !Array.isArray(value)) {
+        return {
+          embedded: Object.keys(value ?? {})
+        }
+      } else {
+        return {}
+      }
+    }
+  })
+  .after((_) => {
+    const data = app.overview<{}, { embedded: string[] }>()
+
+    expectType<OverviewStructure<{}, { embedded: string[] }>>(data)
+    expectAssignable<{ type: string, name: string, embedded: string[] }>(data.decorators!.decorate[0]!)
+    expectAssignable<{ type: string, name: string, embedded: string[] }>(data.decorators!.decorateRequest[0]!)
+    expectAssignable<{ type: string, name: string, embedded: string[] }>(data.decorators!.decorateReply[0]!)
+  })
+  .ready()
+
+app
+  .register(fastifyOverview, {
+    onDecorateDefinition: (type, name, value) => {
+      if (type === 'decorate') {
+        if (typeof value === 'object' && !Array.isArray(value)) {
+          return {
+            embedded: Object.keys(value ?? {})
+          }
+        } else {
+          return {}
+        }
+      } else if (type === 'decorateRequest') {
+        if (typeof value === 'object' && !Array.isArray(value)) {
+          return {
+            recursiveNum: Object.keys(value ?? {}).length
+          }
+        } else {
+          return {}
+        }
+      } else {
+        return {}
+      }
+    }
+  })
+  .after((_) => {
+    const data = app.overview<{}, { instance: { embedded: string[] }, request: { recursiveNum: number } }>()
+
+    expectType<OverviewStructure<{}, { instance: { embedded: string[] }, request: { recursiveNum: number } }>>(data)
+
+    expectAssignable<{ type: string, name: string, embedded: string[] }>(data.decorators!.decorate[0]!)
+    expectError<{ type: string, name: string, embedded: string[] }>(data.decorators!.decorateRequest[0]!)
+    expectError<{ type: string, name: string, embedded: string[] }>(data.decorators!.decorateReply[0]!)
+
+    expectAssignable<{ type: string, name: string, recursiveNum: number }>(data.decorators!.decorateRequest[0]!)
+    expectError<{ type: string, name: string, recursiveNum: number }>(data.decorators!.decorate[0]!)
+    expectError<{ type: string, name: string, recursiveNum: number }>(data.decorators!.decorateReply[0]!)
+  })
+  .ready()