diff --git a/packages/react-pages/client.ts b/packages/react-pages/client.ts
index d3539a93..c9046932 100644
--- a/packages/react-pages/client.ts
+++ b/packages/react-pages/client.ts
@@ -39,5 +39,5 @@ export const IS_SSR = process.env.VITE_PAGES_IS_SSR === 'true'
  */
 export function registerSSRPlugin(importSSRPlugin: () => Promise<SSRPlugin>) {
   const impl = (global as any)['register_vite_pages_ssr_plugin']
-  return impl(importSSRPlugin)
+  return impl?.(importSSRPlugin)
 }