diff --git a/packages/runtime-core/src/compat/renderFn.ts b/packages/runtime-core/src/compat/renderFn.ts
index 44df5cbe8..c65cc8d79 100644
--- a/packages/runtime-core/src/compat/renderFn.ts
+++ b/packages/runtime-core/src/compat/renderFn.ts
@@ -39,7 +39,7 @@ import {
 } from './compatConfig'
 import { compatModelEventPrefix } from './componentVModel'
 
-const v3CompiledRenderFnRE = /^(?:function \w+)?\(_ctx, _cache/
+const v3CompiledRenderFnRE = /^(?:function \w*)?\(_ctx, _cache/
 
 export function convertLegacyRenderFn(instance: ComponentInternalInstance) {
   const Component = instance.type as ComponentOptions