diff --git a/lib/prepare.js b/lib/prepare.js
index 2d0fc56db2..ce8371b9cd 100644
--- a/lib/prepare.js
+++ b/lib/prepare.js
@@ -236,7 +236,7 @@ async function genComponentRegistrationFile ({ sourceDir }) {
   return `import Vue from 'vue'\n` + components.map(genImport).join('\n')
 }
 
-const indexRE = /\b(index|readme)\.md$/i
+const indexRE = /(?<=(^|\/))(index|readme)\.md$/i
 const extRE = /\.(vue|md)$/
 
 function fileToPath (file) {