diff --git a/README.md b/README.md
index 5aa041c..e587530 100644
--- a/README.md
+++ b/README.md
@@ -34,7 +34,7 @@
 This created `index.js` with:
 
 ```js
-'create index';
+// @create-index
 
 export bar from './bar.js';
 export foo from './foo.js';
@@ -64,7 +64,7 @@ Lets create a new file and re-run `create-index`:
 This have updated `index.js` file:
 
 ```js
-'create index';
+// @create-index
 
 export bar from './bar.js';
 export baz from './baz.js';
@@ -152,10 +152,10 @@ Note that the `writeIndex` function is synchronous.
 If there is no `./index.js`, it will create a new file, e.g.
 
 ```js
-'create index';
+// @create-index
 ```
 
-Created index file must start with `'create index';\n\n`. This is used to make sure that `create-index` does not accidentally overwrite your local files.
+Created index file must start with `// @create-index\n\n`. This is used to make sure that `create-index` does not accidentally overwrite your local files.
 
 If there are sibling files, index file will `import` them and `export`, e.g.
 
diff --git a/src/utilities/validateTargetDirectory.js b/src/utilities/validateTargetDirectory.js
index 7304ad3..4f917fa 100644
--- a/src/utilities/validateTargetDirectory.js
+++ b/src/utilities/validateTargetDirectory.js
@@ -25,7 +25,7 @@ export default (targetDirectory) => {
 
   const indexFile = fs.readFileSync(indexFilePath, 'utf8');
 
-  if (!_.startsWith(indexFile, '\'create index\';\n')) {
+  if (!_.startsWith(indexFile, '// @create-index\n')) {
     throw new Error('"' + indexFilePath + '" unsafe index.');
   }
 
diff --git a/test/fixtures/find-index-files/do-not-find-no-index/not-index.js b/test/fixtures/find-index-files/do-not-find-no-index/not-index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/find-index-files/do-not-find-no-index/not-index.js
+++ b/test/fixtures/find-index-files/do-not-find-no-index/not-index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/find-index-files/do-not-find/index.js b/test/fixtures/find-index-files/do-not-find/index.js
index e884c1f..223bc91 100644
--- a/test/fixtures/find-index-files/do-not-find/index.js
+++ b/test/fixtures/find-index-files/do-not-find/index.js
@@ -1 +1 @@
-// 'create index';
+// create-index
diff --git a/test/fixtures/find-index-files/find-1/index.js b/test/fixtures/find-index-files/find-1/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/find-index-files/find-1/index.js
+++ b/test/fixtures/find-index-files/find-1/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/find-index-files/nested/do-not-find/index.js b/test/fixtures/find-index-files/nested/do-not-find/index.js
index e884c1f..223bc91 100644
--- a/test/fixtures/find-index-files/nested/do-not-find/index.js
+++ b/test/fixtures/find-index-files/nested/do-not-find/index.js
@@ -1 +1 @@
-// 'create index';
+// create-index
diff --git a/test/fixtures/find-index-files/nested/find-2/index.js b/test/fixtures/find-index-files/nested/find-2/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/find-index-files/nested/find-2/index.js
+++ b/test/fixtures/find-index-files/nested/find-2/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/find-index-files/nested/find-3/index.js b/test/fixtures/find-index-files/nested/find-3/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/find-index-files/nested/find-3/index.js
+++ b/test/fixtures/find-index-files/nested/find-3/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories-and-files/foo/index.js b/test/fixtures/read-directory/children-directories-and-files/foo/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories-and-files/foo/index.js
+++ b/test/fixtures/read-directory/children-directories-and-files/foo/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories-unsafe-name/bar-bar/index.js b/test/fixtures/read-directory/children-directories-unsafe-name/bar-bar/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories-unsafe-name/bar-bar/index.js
+++ b/test/fixtures/read-directory/children-directories-unsafe-name/bar-bar/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories-unsafe-name/foo-foo/index.js b/test/fixtures/read-directory/children-directories-unsafe-name/foo-foo/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories-unsafe-name/foo-foo/index.js
+++ b/test/fixtures/read-directory/children-directories-unsafe-name/foo-foo/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories-unsafe-name/present/index.js b/test/fixtures/read-directory/children-directories-unsafe-name/present/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories-unsafe-name/present/index.js
+++ b/test/fixtures/read-directory/children-directories-unsafe-name/present/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories-without-index/bar/bar.js b/test/fixtures/read-directory/children-directories-without-index/bar/bar.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories-without-index/bar/bar.js
+++ b/test/fixtures/read-directory/children-directories-without-index/bar/bar.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories-without-index/foo/foo.js b/test/fixtures/read-directory/children-directories-without-index/foo/foo.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories-without-index/foo/foo.js
+++ b/test/fixtures/read-directory/children-directories-without-index/foo/foo.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories-without-index/present.js b/test/fixtures/read-directory/children-directories-without-index/present.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories-without-index/present.js
+++ b/test/fixtures/read-directory/children-directories-without-index/present.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories/bar/index.js b/test/fixtures/read-directory/children-directories/bar/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories/bar/index.js
+++ b/test/fixtures/read-directory/children-directories/bar/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-directories/foo/index.js b/test/fixtures/read-directory/children-directories/foo/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-directories/foo/index.js
+++ b/test/fixtures/read-directory/children-directories/foo/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-index/bar/index.js b/test/fixtures/read-directory/children-index/bar/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-index/bar/index.js
+++ b/test/fixtures/read-directory/children-index/bar/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-index/foo/index.js b/test/fixtures/read-directory/children-index/foo/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-index/foo/index.js
+++ b/test/fixtures/read-directory/children-index/foo/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/read-directory/children-index/index.js b/test/fixtures/read-directory/children-index/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/read-directory/children-index/index.js
+++ b/test/fixtures/read-directory/children-index/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/validate-target-directory/safe-index/index.js b/test/fixtures/validate-target-directory/safe-index/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/validate-target-directory/safe-index/index.js
+++ b/test/fixtures/validate-target-directory/safe-index/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/write-index/mixed/bar/index.js b/test/fixtures/write-index/mixed/bar/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/write-index/mixed/bar/index.js
+++ b/test/fixtures/write-index/mixed/bar/index.js
@@ -1 +1 @@
-'create index';
+// @create-index
diff --git a/test/fixtures/write-index/mixed/foo/index.js b/test/fixtures/write-index/mixed/foo/index.js
index a45ca72..b83b7f9 100644
--- a/test/fixtures/write-index/mixed/foo/index.js
+++ b/test/fixtures/write-index/mixed/foo/index.js
@@ -1 +1 @@
-'create index';
+// @create-index