diff --git a/packages/react-pages/src/node/index.ts b/packages/react-pages/src/node/index.ts
index a88f75f5..8791c12b 100644
--- a/packages/react-pages/src/node/index.ts
+++ b/packages/react-pages/src/node/index.ts
@@ -104,7 +104,7 @@ function pluginFactory(opts: PluginConfig = {}): Plugin {
       },
       define: {
         __HASH_ROUTER__: !!useHashRouter,
-        'process.env.VITE_PAGES_IS_SSR': env.ssrBuild
+        'process.env.VITE_PAGES_IS_SSR': config.build?.ssr
           ? JSON.stringify('true')
           : JSON.stringify('false'),
       },