diff --git a/packages/reactivity/__tests__/reactiveArray.spec.ts b/packages/reactivity/__tests__/reactiveArray.spec.ts
index 1c6fcefd592..d405608f8c4 100644
--- a/packages/reactivity/__tests__/reactiveArray.spec.ts
+++ b/packages/reactivity/__tests__/reactiveArray.spec.ts
@@ -99,6 +99,21 @@ describe('reactivity/reactive/Array', () => {
     expect(fn).toHaveBeenCalledTimes(1)
   })
 
+  test("should reactive when mutate array's index", () => {
+    const original = [1, 2, 3]
+    const observed = reactive(original)
+
+    let dummy
+    effect(() => {
+      dummy = observed.hasOwnProperty(0)
+    })
+
+    expect(dummy).toBe(true)
+
+    delete observed[0]
+    expect(dummy).toBe(false)
+  })
+
   test('shift on Array should trigger dependency once', () => {
     const arr = reactive([1, 2, 3])
     const fn = vi.fn()
diff --git a/packages/reactivity/src/baseHandlers.ts b/packages/reactivity/src/baseHandlers.ts
index 7cee7aa9bd5..36707aa9138 100644
--- a/packages/reactivity/src/baseHandlers.ts
+++ b/packages/reactivity/src/baseHandlers.ts
@@ -80,10 +80,12 @@ function createArrayInstrumentations() {
   return instrumentations
 }
 
-function hasOwnProperty(this: object, key: string) {
+function hasOwnProperty(this: object, key: unknown) {
+  // #10455 hasOwnProperty may be called with non-string values
+  key = '' + key
   const obj = toRaw(this)
   track(obj, TrackOpTypes.HAS, key)
-  return obj.hasOwnProperty(key)
+  return obj.hasOwnProperty(key as string)
 }
 
 class BaseReactiveHandler implements ProxyHandler<Target> {