diff --git a/scripts/build-success.sh b/scripts/build-success.sh
index 75371b0..e9f7ae6 100644
--- a/scripts/build-success.sh
+++ b/scripts/build-success.sh
@@ -7,3 +7,7 @@ echo '{"type":"module"}' > dist/esm/package.json
 cp dist/index.js dist/backup-index.js
 cp dist/index.d.ts dist/backup-index.d.ts
 cp dist/esm/index.js dist/esm/backup-index.js
+
+echo '\n// backup' >> dist/backup-index.js
+echo '\n// backup' >> dist/esm/backup-index.js
+echo '\n// backup' >> dist/backup-index.d.ts
diff --git a/test/lib/rebuild-dist.test.ts b/test/lib/rebuild-dist.test.ts
index 0ffb13b..1967027 100644
--- a/test/lib/rebuild-dist.test.ts
+++ b/test/lib/rebuild-dist.test.ts
@@ -61,7 +61,9 @@ test('内容写入文件', async () => {
     foo,
       aaaaa
     });
-    //# sourceMappingURL=index.js.map"
+    //# sourceMappingURL=index.js.map
+    // backup
+    "
   `);
 
   await expect(readFile(path.join(distDir, 'index.d.ts'), 'utf8')).resolves
@@ -72,6 +74,8 @@ test('内容写入文件', async () => {
 
     export { aaaaa };
 
+    // backup
+
     declare const foo = { bar: "baz" };
     export { foo };"
   `);
@@ -84,6 +88,8 @@ test('内容写入文件', async () => {
       aaaaa
     };
     //# sourceMappingURL=index.js.map
+    // backup
+
     var foo = { bar: "baz" }
     export { foo };"
   `);