diff --git a/index.js b/index.js
index 52a6b93bf83194f2b82c83455a01053fef6e8b9e..ccbf68f3c378bb95da8030183c16abc76e3add7d 100644
--- a/index.js
+++ b/index.js
@@ -13,7 +13,7 @@ module.exports = {
         return code;
       },
       {
-        exts: ['.svelte'],
+        exts: config.svelte.exts || ['.svelte'],
       }
     );
   },