diff --git a/source/index.ts b/source/index.ts
index 20b1674..e4085d0 100644
--- a/source/index.ts
+++ b/source/index.ts
@@ -47,7 +47,7 @@ export type Variable = {
 export const DEFAULT_VARIABLE: Variable = {
   source: 'build',
   output: 'lib',
-  buildSource: 'buildSource',
+  buildSource: 'src',
 };
 
 /**