diff --git a/src/js_object_accessor.hpp b/src/js_object_accessor.hpp
index cccf6e23..bcfc06fb 100644
--- a/src/js_object_accessor.hpp
+++ b/src/js_object_accessor.hpp
@@ -122,14 +122,16 @@ struct NativeAccessor {
     }
     static size_t to_existing_object_index(ContextType ctx, SharedRealm realm, ValueType &value) {
         ObjectType object = Value::validated_to_object(ctx, value);
-        if (Object::template is_instance<RealmObjectClass<T>>(ctx, object)) {
-            auto realm_object = get_internal<T, RealmObjectClass<T>>(object);
-            if (realm_object->realm() == realm) {
-                return realm_object->row().get_index();
-            }
-            throw std::runtime_error("Realm object is from another Realm");
+        if (!Object::template is_instance<RealmObjectClass<T>>(ctx, object)) {
+            throw std::runtime_error("object is not a Realm Object");
         }
-        throw std::runtime_error("object is not a Realm Object");
+        
+        auto realm_object = get_internal<T, RealmObjectClass<T>>(object);
+        if (realm_object->realm() != realm) {
+            throw std::runtime_error("Realm object is from another Realm");
+
+        }
+        return realm_object->row().get_index();
     }
     static ValueType from_object(ContextType ctx, realm::Object realm_object) {
         return RealmObjectClass<T>::create_instance(ctx, std::move(realm_object));