diff --git a/src/reactivity/reactive.ts b/src/reactivity/reactive.ts
index 827223f6..4691011e 100644
--- a/src/reactivity/reactive.ts
+++ b/src/reactivity/reactive.ts
@@ -16,13 +16,19 @@ import { rawSet, accessModifiedSet } from '../utils/sets'
 
 export function isRaw(obj: any): boolean {
   return Boolean(
-    obj?.__ob__ && typeof obj.__ob__ === 'object' && obj.__ob__?.__raw__
+    obj &&
+      hasOwn(obj, '__ob__') &&
+      typeof obj.__ob__ === 'object' &&
+      obj.__ob__?.__raw__
   )
 }
 
 export function isReactive(obj: any): boolean {
   return Boolean(
-    obj?.__ob__ && typeof obj.__ob__ === 'object' && !obj.__ob__?.__raw__
+    obj &&
+      hasOwn(obj, '__ob__') &&
+      typeof obj.__ob__ === 'object' &&
+      !obj.__ob__?.__raw__
   )
 }
 
diff --git a/test/v3/reactivity/reactive.spec.ts b/test/v3/reactivity/reactive.spec.ts
index 4ae2e7de..7719a1e9 100644
--- a/test/v3/reactivity/reactive.spec.ts
+++ b/test/v3/reactivity/reactive.spec.ts
@@ -8,6 +8,7 @@ import {
   shallowReactive,
   set,
   markRaw,
+  isRaw,
 } from '../../../src'
 
 describe('reactivity/reactive', () => {
@@ -35,6 +36,22 @@ describe('reactivity/reactive', () => {
     expect(Object.keys(observed)).toEqual(['foo'])
   })
 
+  //#693
+  test('the hasOwn should be used to determine whether an attribute exists.', () => {
+    const obj = {}
+    expect(isReactive(obj)).toBe(false)
+    expect(isRaw(obj)).toBe(false)
+    const mockObj = new Proxy(obj, {
+      get: (target, key) => {
+        if (!(key in Object.keys(target))) {
+          throw new Error(`the ${key.toString()} is not found in the target.`)
+        }
+      },
+    })
+    expect(isReactive(mockObj)).toBe(false)
+    expect(isRaw(obj)).toBe(false)
+  })
+
   test('proto', () => {
     const obj = {}
     const reactiveObj = reactive(obj)