diff --git a/components/upload/demo/upload-manually.vue b/components/upload/demo/upload-manually.vue
index 6e76a8ed3..4276de4dd 100644
--- a/components/upload/demo/upload-manually.vue
+++ b/components/upload/demo/upload-manually.vue
@@ -52,7 +52,7 @@ const handleRemove: UploadProps['onRemove'] = file => {
 };
 
 const beforeUpload: UploadProps['beforeUpload'] = file => {
-  fileList.value = [...fileList.value, file];
+  fileList.value = [...(fileList.value || []), file];
   return false;
 };