diff --git a/runtime/tmagic-form/src/useFormConfig.ts b/runtime/tmagic-form/src/useFormConfig.ts
index d966b873..c99b49e7 100644
--- a/runtime/tmagic-form/src/useFormConfig.ts
+++ b/runtime/tmagic-form/src/useFormConfig.ts
@@ -23,7 +23,7 @@ export const useFormConfig = (props: AppProps) => {
   // @ts-ignore
   const formConfig = computed(() => props.fillConfig((config.value?.items || []) as FormConfig, mForm));
 
-  const app = new Core({
+  const app: Core | undefined = new Core({
     ua: contentWindow?.navigator.userAgent,
     platform: 'editor',
   });