diff --git a/.changeset/fair-donuts-chew.md b/.changeset/fair-donuts-chew.md
new file mode 100644
index 000000000..6b6906449
--- /dev/null
+++ b/.changeset/fair-donuts-chew.md
@@ -0,0 +1,6 @@
+---
+'@tanstack/react-pacer': patch
+'@tanstack/preact-pacer': patch
+---
+
+Use the latest `onUnmount` callback during cleanup so adapter teardown reflects current options instead of the initial render.
diff --git a/packages/preact-pacer/src/debouncer/useDebouncer.ts b/packages/preact-pacer/src/debouncer/useDebouncer.ts
index 198ff79df..a3ab3c1ee 100644
--- a/packages/preact-pacer/src/debouncer/useDebouncer.ts
+++ b/packages/preact-pacer/src/debouncer/useDebouncer.ts
@@ -1,4 +1,4 @@
-import { useEffect, useMemo, useState } from 'preact/hooks'
+import { useEffect, useMemo, useRef, useState } from 'preact/hooks'
 import { Debouncer } from '@tanstack/pacer/debouncer'
 import { shallow, useSelector } from '@tanstack/preact-store'
 import { useDefaultPacerOptions } from '../provider/PacerProvider'
@@ -193,12 +193,14 @@ export function useDebouncer<TFn extends AnyFunction, TSelected = {}>(
 
   debouncer.fn = fn
   debouncer.setOptions(mergedOptions)
+  const onUnmountRef = useRef(mergedOptions.onUnmount)
+  onUnmountRef.current = mergedOptions.onUnmount
 
   /* eslint-disable react-hooks/exhaustive-deps -- cleanup only; runs on unmount */
   useEffect(() => {
     return () => {
-      if (mergedOptions.onUnmount) {
-        mergedOptions.onUnmount(debouncer)
+      if (onUnmountRef.current) {
+        onUnmountRef.current(debouncer)
       } else {
         debouncer.cancel()
       }
diff --git a/packages/react-pacer/src/async-debouncer/useAsyncDebouncer.ts b/packages/react-pacer/src/async-debouncer/useAsyncDebouncer.ts
index 795b89acf..9d3947de5 100644
--- a/packages/react-pacer/src/async-debouncer/useAsyncDebouncer.ts
+++ b/packages/react-pacer/src/async-debouncer/useAsyncDebouncer.ts
@@ -1,4 +1,4 @@
-import { useEffect, useMemo, useState } from 'react'
+import { useEffect, useMemo, useRef, useState } from 'react'
 import { AsyncDebouncer } from '@tanstack/pacer/async-debouncer'
 import { shallow, useSelector } from '@tanstack/react-store'
 import { useDefaultPacerOptions } from '../provider/PacerProvider'
@@ -248,6 +248,8 @@ export function useAsyncDebouncer<TFn extends AnyAsyncFunction, TSelected = {}>(
 
   asyncDebouncer.fn = fn
   asyncDebouncer.setOptions(mergedOptions)
+  const onUnmountRef = useRef(mergedOptions.onUnmount)
+  onUnmountRef.current = mergedOptions.onUnmount
 
   const state = useSelector(asyncDebouncer.store, selector, {
     compare: shallow,
@@ -256,8 +258,8 @@ export function useAsyncDebouncer<TFn extends AnyAsyncFunction, TSelected = {}>(
   /* eslint-disable react-hooks/exhaustive-deps, @eslint-react/exhaustive-deps, react-compiler/react-compiler -- unmount cleanup only; empty deps keep teardown stable */
   useEffect(() => {
     return () => {
-      if (mergedOptions.onUnmount) {
-        mergedOptions.onUnmount(asyncDebouncer)
+      if (onUnmountRef.current) {
+        onUnmountRef.current(asyncDebouncer)
       } else {
         asyncDebouncer.cancel()
         asyncDebouncer.abort()
diff --git a/packages/react-pacer/src/debouncer/useDebouncer.ts b/packages/react-pacer/src/debouncer/useDebouncer.ts
index 903d7e351..ea75c4b05 100644
--- a/packages/react-pacer/src/debouncer/useDebouncer.ts
+++ b/packages/react-pacer/src/debouncer/useDebouncer.ts
@@ -1,4 +1,4 @@
-import { useEffect, useMemo, useState } from 'react'
+import { useEffect, useMemo, useRef, useState } from 'react'
 import { Debouncer } from '@tanstack/pacer/debouncer'
 import { shallow, useSelector } from '@tanstack/react-store'
 import { useDefaultPacerOptions } from '../provider/PacerProvider'
@@ -194,12 +194,14 @@ export function useDebouncer<TFn extends AnyFunction, TSelected = {}>(
 
   debouncer.fn = fn
   debouncer.setOptions(mergedOptions)
+  const onUnmountRef = useRef(mergedOptions.onUnmount)
+  onUnmountRef.current = mergedOptions.onUnmount
 
   /* eslint-disable react-hooks/exhaustive-deps, @eslint-react/exhaustive-deps, react-compiler/react-compiler -- unmount cleanup only; empty deps keep teardown stable */
   useEffect(() => {
     return () => {
-      if (mergedOptions.onUnmount) {
-        mergedOptions.onUnmount(debouncer)
+      if (onUnmountRef.current) {
+        onUnmountRef.current(debouncer)
       } else {
         debouncer.cancel()
       }
diff --git a/packages/react-pacer/src/rate-limiter/useRateLimiter.ts b/packages/react-pacer/src/rate-limiter/useRateLimiter.ts
index 090656eaa..0259f85ec 100644
--- a/packages/react-pacer/src/rate-limiter/useRateLimiter.ts
+++ b/packages/react-pacer/src/rate-limiter/useRateLimiter.ts
@@ -1,4 +1,4 @@
-import { useEffect, useMemo, useState } from 'react'
+import { useEffect, useMemo, useRef, useState } from 'react'
 import { RateLimiter } from '@tanstack/pacer/rate-limiter'
 import { shallow, useSelector } from '@tanstack/react-store'
 import { useDefaultPacerOptions } from '../provider/PacerProvider'
@@ -221,12 +221,14 @@ export function useRateLimiter<TFn extends AnyFunction, TSelected = {}>(
 
   rateLimiter.fn = fn
   rateLimiter.setOptions(mergedOptions)
+  const onUnmountRef = useRef(mergedOptions.onUnmount)
+  onUnmountRef.current = mergedOptions.onUnmount
 
   /* eslint-disable react-hooks/exhaustive-deps, @eslint-react/exhaustive-deps, react-compiler/react-compiler -- unmount cleanup only; empty deps keep teardown stable */
   useEffect(() => {
     return () => {
-      if (mergedOptions.onUnmount) {
-        mergedOptions.onUnmount(rateLimiter)
+      if (onUnmountRef.current) {
+        onUnmountRef.current(rateLimiter)
       }
     }
   }, [])