diff --git a/ecmascript/js_object.cpp b/ecmascript/js_object.cpp
index 0b4d939cd407fe599703afaa683d549372298c77..d5318f8703e623034724adba77df0a8c09ea6c5a 100644
--- a/ecmascript/js_object.cpp
+++ b/ecmascript/js_object.cpp
@@ -2485,17 +2485,26 @@ JSHandle<JSForInIterator> JSObject::EnumerateObjectProperties(JSThread *thread,
 JSHandle<JSForInIterator> JSObject::LoadEnumerateProperties(JSThread *thread, const JSHandle<JSTaggedValue> &object)
 {
     PropertyAccessor accessor(thread, object);
-    JSHandle<JSTaggedValue> fastKeys = accessor.GetKeysFast();
-    RETURN_HANDLE_IF_ABRUPT_COMPLETION(JSForInIterator, thread);
     JSMutableHandle<JSTaggedValue> keys(thread, JSTaggedValue::Undefined());
     JSMutableHandle<JSTaggedValue> cachedHclass(thread, JSTaggedValue::Undefined());
-    if (fastKeys->IsUndefined()) {
+    auto *hclass = object->GetTaggedObject()->GetClass();
+    auto env = thread->GetEcmaVM()->GetGlobalEnv();
+    if (JSObject::Cast(hclass->GetPrototype().GetTaggedObject())->GetClass() != 
+        env->GetObjectFunctionPrototypeClass().GetObject<JSHClass>()) {
         keys.Update(accessor.GetKeysSlow());
-        RETURN_HANDLE_IF_ABRUPT_COMPLETION(JSForInIterator, thread);
-    } else {
-        keys.Update(fastKeys);
         cachedHclass.Update(accessor.GetCachedHclass());
     }
+    else {
+        JSHandle<JSTaggedValue> fastKeys = accessor.GetKeysFast();
+        RETURN_HANDLE_IF_ABRUPT_COMPLETION(JSForInIterator, thread);
+        if (fastKeys->IsUndefined()) {
+            keys.Update(accessor.GetKeysSlow());
+            RETURN_HANDLE_IF_ABRUPT_COMPLETION(JSForInIterator, thread);
+        } else {
+            keys.Update(fastKeys);
+            cachedHclass.Update(accessor.GetCachedHclass());
+        }
+    }
     return thread->GetEcmaVM()->GetFactory()->NewJSForinIterator(object, keys, cachedHclass);
 }