diff --git a/packages/hydration/hydration.ts b/packages/hydration/hydration.ts
index 6c4bfc68..ead42d19 100644
--- a/packages/hydration/hydration.ts
+++ b/packages/hydration/hydration.ts
@@ -1,38 +1,39 @@
-import { AsyncFrameworkFn, FrameworkFn, Component, AsyncComponent, Props, Slots } from './types'
+import type { AsyncComponent, AsyncFrameworkFn, Component, EnhanceIslands, FrameworkFn, Props, Slots } from './types'
+
 export { Framework, Props, Slots } from './types'
 
 const findById = (id: string) =>
   document.getElementById(id) || console.error(`Missing #${id}, could not mount island.`)
 
 // Public: Hydrates the component immediately.
-export function hydrateNow (framework: FrameworkFn, component: Component, id: string, props: Props, slots: Slots) {
+export function hydrateNow (framework: FrameworkFn, component: Component, id: string, props: Props, slots: Slots, enhanceIslands: EnhanceIslands) {
   const el = findById(id)
   if (el) {
-    framework(component, id, el, props, slots)
+    framework(component, id, el, props, slots, enhanceIslands)
     el.setAttribute('hydrated', '')
   }
 }
 
-async function resolveAndHydrate (frameworkFn: AsyncFrameworkFn, componentFn: AsyncComponent, id: string, props: Props, slots: Slots) {
+async function resolveAndHydrate (frameworkFn: AsyncFrameworkFn, componentFn: AsyncComponent, id: string, props: Props, slots: Slots, enhanceIslands: EnhanceIslands) {
   const [framework, component] = await Promise.all([frameworkFn(), componentFn()])
-  hydrateNow(framework, component, id, props, slots)
+  hydrateNow(framework, component, id, props, slots, enhanceIslands)
 }
 
 // Public: Hydrate this component as soon as the main thread is free.
 // If `requestIdleCallback` isn't supported, it uses a small delay.
-export function hydrateWhenIdle (framework: AsyncFrameworkFn, component: AsyncComponent, id: string, props: Props, slots: Slots) {
+export function hydrateWhenIdle (framework: AsyncFrameworkFn, component: AsyncComponent, id: string, props: Props, slots: Slots, enhanceIslands: EnhanceIslands) {
   const whenIdle = window.requestIdleCallback || setTimeout
   const cancelIdle = window.cancelIdleCallback || clearTimeout
 
   const idleId: any = whenIdle(() =>
-    resolveAndHydrate(framework, component, id, props, slots))
+    resolveAndHydrate(framework, component, id, props, slots, enhanceIslands))
 
   if (import.meta.env.DISPOSE_ISLANDS)
     onDispose(id, () => cancelIdle(idleId))
 }
 
 // Public: Hydrate this component when the specified media query is matched.
-export function hydrateOnMediaQuery (framework: AsyncFrameworkFn, component: AsyncComponent, id: string, props: Props, slots: Slots) {
+export function hydrateOnMediaQuery (framework: AsyncFrameworkFn, component: AsyncComponent, id: string, props: Props, slots: Slots, enhanceIslands: EnhanceIslands) {
   const mediaQuery = matchMedia(props._mediaQuery as string)
   delete props._mediaQuery
 
@@ -40,7 +41,7 @@ export function hydrateOnMediaQuery (framework: AsyncFrameworkFn, component: Asy
 
   const hydrate = () => {
     onChange()
-    resolveAndHydrate(framework, component, id, props, slots)
+    resolveAndHydrate(framework, component, id, props, slots, enhanceIslands)
   }
 
   mediaQuery.matches ? hydrate() : onChange(hydrate)
@@ -50,7 +51,7 @@ export function hydrateOnMediaQuery (framework: AsyncFrameworkFn, component: Asy
 }
 
 // Public: Hydrate this component when one of it's children becomes visible.
-export function hydrateWhenVisible (framework: AsyncFrameworkFn, component: AsyncComponent, id: string, props: Props, slots: Slots) {
+export function hydrateWhenVisible (framework: AsyncFrameworkFn, component: AsyncComponent, id: string, props: Props, slots: Slots, enhanceIslands: EnhanceIslands) {
   const el = findById(id)
   if (el) {
     // NOTE: Force detection of the element for non-Vue frameworks.
@@ -65,7 +66,7 @@ export function hydrateWhenVisible (framework: AsyncFrameworkFn, component: Asyn
         if (import.meta.env.DEV)
           el.style.display = ''
 
-        resolveAndHydrate(framework, component, id, props, slots)
+        resolveAndHydrate(framework, component, id, props, slots, enhanceIslands)
       }
     })
     const stopObserver = () => observer.disconnect()
@@ -79,4 +80,4 @@ export function hydrateWhenVisible (framework: AsyncFrameworkFn, component: Asyn
 
 // Internal: Invoked before navigation when turbo is enabled, or before HMR.
 export const onDispose = (id: string, fn: () => void) =>
-  (window as any).__ILE_DISPOSE__?.set(id, fn)
+  (window as any).__ILE_DISPOSE__?.set(id, fn)
\ No newline at end of file
diff --git a/packages/hydration/types.ts b/packages/hydration/types.ts
index ddf1e8d2..008e0ef2 100644
--- a/packages/hydration/types.ts
+++ b/packages/hydration/types.ts
@@ -2,6 +2,8 @@
 
 import type Vue from './vue'
 
+export type { EnhanceIslands } from '../iles/types/shared'
+
 export type Framework = 'vue' | 'preact' | 'solid' | 'svelte' | 'vanilla'
 export type FrameworkFn = typeof Vue
 export type AsyncFrameworkFn = () => Promise<FrameworkFn>
diff --git a/packages/hydration/vue.ts b/packages/hydration/vue.ts
index 1948c7dc..819e7de4 100644
--- a/packages/hydration/vue.ts
+++ b/packages/hydration/vue.ts
@@ -1,12 +1,12 @@
-import { h, createApp as createClientApp, createStaticVNode, createSSRApp } from 'vue'
-import type { DefineComponent as Component, Component as App } from 'vue'
-import type { Props, Slots } from './types'
+import { createApp as createClientApp, createSSRApp, createStaticVNode, h } from 'vue'
+import type { Component as App, DefineComponent as Component } from 'vue'
+import type { EnhanceIslands, Props, Slots } from './types'
 import { onDispose } from './hydration'
 
 const createVueApp = import.meta.env.SSR ? createSSRApp : createClientApp
 
 // Internal: Creates a Vue app and mounts it on the specified island root.
-export default function createVueIsland (component: Component, id: string, el: Element, props: Props, slots: Slots | undefined) {
+export default async function createVueIsland (component: Component, id: string, el: Element, props: Props, slots: Slots | undefined, enhanceIslands: EnhanceIslands) {
   const slotFns = slots && Object.fromEntries(Object.entries(slots).map(([slotName, content]) => {
     return [slotName, () => (createStaticVNode as any)(content)]
   }))
@@ -17,6 +17,9 @@ export default function createVueIsland (component: Component, id: string, el: E
     appDefinition.name = `Island: ${nameFromFile(component.__file)}`
 
   const app = createVueApp(appDefinition)
+  if (enhanceIslands)
+    await enhanceIslands({ app })
+  
   app.mount(el!, Boolean(slots))
 
   if (import.meta.env.DISPOSE_ISLANDS)
@@ -29,4 +32,4 @@ export default function createVueIsland (component: Component, id: string, el: E
 function nameFromFile (file?: string) {
   const regex = /(\w+?)(?:\.vue)?$/
   return file?.match(regex)?.[1] || file
-}
+}
\ No newline at end of file
diff --git a/packages/iles/src/client/app/components/Island.vue b/packages/iles/src/client/app/components/Island.vue
index d8978932..f95f64a4 100644
--- a/packages/iles/src/client/app/components/Island.vue
+++ b/packages/iles/src/client/app/components/Island.vue
@@ -83,6 +83,7 @@ export default defineComponent({
     const { _, ...slots } = this.$slots
     const slotVNodes = mapObject(slots, slotFn => slotFn?.())
     const hydrationPkg = `${isSSR ? '' : '/@id/'}@islands/hydration`
+    const userAppPkg = `${isSSR ? '@islands/user-app' : '/@id/virtual:user-app'}`
     let renderedSlots: Record<string, string>
 
     const renderSlots = async () =>
@@ -94,13 +95,16 @@ export default defineComponent({
       const frameworkPath = `${hydrationPkg}/${this.framework}`
 
       return `import { ${hydrationFns[this.strategy]} as hydrate } from '${hydrationPkg}'
+import userApp from '${userAppPkg}'
+
+const { enhanceIslands } = userApp
 ${isEager(this.strategy)
     ? `import framework from '${frameworkPath}'
 import { ${this.importName} as component } from '${componentPath}'`
     : `const framework = async () => (await import('${frameworkPath}')).default
 const component = async () => (await import('${componentPath}')).${this.importName}`
 }
-hydrate(framework, component, '${this.id}', ${serialize(props)}, ${serialize(slots)})
+hydrate(framework, component, '${this.id}', ${serialize(props)}, ${serialize(slots)}, enhanceIslands)
   `
     }
 
diff --git a/packages/iles/src/client/app/index.ts b/packages/iles/src/client/app/index.ts
index d175c9e7..ba468875 100644
--- a/packages/iles/src/client/app/index.ts
+++ b/packages/iles/src/client/app/index.ts
@@ -17,7 +17,7 @@ import { resolveProps } from './props'
 
 const newApp = import.meta.env.SSR ? createSSRApp : createClientApp
 
-function createRouter (base: string | undefined, routerOptions: Partial<RouterOptions>) {
+function createRouter(base: string | undefined, routerOptions: Partial<RouterOptions>) {
   if (base === '/') base = undefined
 
   return createVueRouter({
@@ -78,7 +78,14 @@ export const createApp: CreateAppFactory = async (options = {}) => {
   // Apply any configuration added by the user in app.ts
   // if (headConfig) useHead(ref(typeof headConfig === 'function' ? headConfig(context) : headConfig))
   if (headConfig) head.push(ref(typeof headConfig === 'function' ? headConfig(context) : headConfig))
-  if (enhanceApp) await enhanceApp(context)
+
+  // enhanceIslands is called on the shell app during development otherwise user will have to duplicate `app.use(pinia)` in both enhanceIslands and enhanceApp
+  if (enhanceIslands) {
+    await enhanceIslands({ app })
+  }
+  if (enhanceApp) {
+    await enhanceApp(context)
+  }
   await installMDXComponents(context, userApp)
 
   return context
diff --git a/packages/iles/types/shared.d.ts b/packages/iles/types/shared.d.ts
index 5c23cf59..7ad55801 100644
--- a/packages/iles/types/shared.d.ts
+++ b/packages/iles/types/shared.d.ts
@@ -181,11 +181,16 @@ export interface IlesModule extends Partial<BaseIlesConfig> {
 }
 
 export type EnhanceAppContext = AppContext
+export type EnhanceApp = (ctx: EnhanceAppContext) => void | Promise<void>
+export type EnhanceIslandContext = IslandContext
+export type EnhanceIslands = (ctx: EnhanceIslandContext) => void | Promise<void>
+
 export type MDXComponents = Record<string, any>
 
 export interface UserApp {
   head?: HeadConfig | ((ctx: EnhanceAppContext) => HeadConfig)
-  enhanceApp?: (ctx: EnhanceAppContext) => void | Promise<void>
+  enhanceApp?: EnhanceApp
+  enhanceIslands?: EnhanceIslands
   mdxComponents?: MDXComponents | ((ctx: EnhanceAppContext) => MDXComponents | Promise<MDXComponents>)
   router?: Omit<VueRouterOptions, 'history', 'routes'>
   socialTags?: boolean