diff --git a/plugins/typescript/index.js b/plugins/typescript/index.js
index <HASH>..<HASH> 100644
--- a/plugins/typescript/index.js
+++ b/plugins/typescript/index.js
@@ -50,7 +50,7 @@ exports.apply = (
       .options(
         Object.assign(
           {
-            transpileOnly: true,
+            transpileOnly: api.config.parallel ? undefined : true,
             appendTsSuffixTo: ['\\.vue$'],
             // https://github.com/TypeStrong/ts-loader#happypackmode-boolean-defaultfalse
             happyPackMode: api.config.parallel
fix(typescript): Don't set `transpileOnly` in parallel mode (#<I>)