diff --git a/packages/runtime-vapor/src/component.ts b/packages/runtime-vapor/src/component.ts
index 5ff3b86b8..68e3c6942 100644
--- a/packages/runtime-vapor/src/component.ts
+++ b/packages/runtime-vapor/src/component.ts
@@ -20,7 +20,7 @@ export type FunctionalComponent = SetupFn & {
 }
 export interface ObjectComponent {
   props: ComponentPropsOptions
-  setup: SetupFn
+  setup?: SetupFn
   render(ctx: any): Block
 }
 
diff --git a/packages/runtime-vapor/src/render.ts b/packages/runtime-vapor/src/render.ts
index 422d5e689..f55acd576 100644
--- a/packages/runtime-vapor/src/render.ts
+++ b/packages/runtime-vapor/src/render.ts
@@ -50,11 +50,10 @@ export function mountComponent(
 
     const setupFn =
       typeof component === 'function' ? component : component.setup
-
-    const state = setupFn(props, ctx)
     instance.proxy = markRaw(
       new Proxy({ _: instance }, PublicInstanceProxyHandlers),
     )
+    const state = setupFn && setupFn(props, ctx)
     if (state && '__isScriptSetup' in state) {
       instance.setupState = proxyRefs(state)
       return (instance.block = component.render(instance.proxy))