diff --git a/packages/plugin-vue/src/index.ts b/packages/plugin-vue/src/index.ts
index f326a4da37918e..58431ab1623569 100644
--- a/packages/plugin-vue/src/index.ts
+++ b/packages/plugin-vue/src/index.ts
@@ -119,6 +119,7 @@ export default function vuePlugin(rawOptions: Options = {}): Plugin {
         define: {
           __VUE_OPTIONS_API__: true,
           __VUE_PROD_DEVTOOLS__: false,
+          __VUE_SSR__: !!config.build?.ssr,
           ...config.define
         },
         ssr: {