diff --git a/packages/compiler-sfc/src/compileScript.ts b/packages/compiler-sfc/src/compileScript.ts
index 5403788ed..de096ced3 100644
--- a/packages/compiler-sfc/src/compileScript.ts
+++ b/packages/compiler-sfc/src/compileScript.ts
@@ -943,7 +943,7 @@ export function compileScript(
 
   let runtimeOptions = ``
   if (vapor) {
-    runtimeOptions += `\n  vapor: true,`
+    runtimeOptions += `\n  __vapor: true,`
   }
   if (!ctx.hasDefaultExportName && filename && filename !== DEFAULT_FILENAME) {
     const match = filename.match(/([^/\\]+)\.\w+$/)