diff --git a/gulpfile.js b/gulpfile.js
index 1906642..6a39a1b 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -25,10 +25,10 @@ gulp.task('validate:config', cb => {
 
 gulp.task('validate:languages', cb => {
   const languagesPath = path.join(__dirname, 'languages');
-  const languages = fs.readdirSync(languagesPath);
   const errors = [];
 
-  languages.forEach(lang => {
+  fs.readdirSync(languagesPath).forEach(lang => {
+    if (!lang.endsWith('.yml')) return;
     const languagePath = path.join(languagesPath, lang);
     try {
       yaml.safeLoad(fs.readFileSync(languagePath), {
diff --git a/languages/README.md b/languages/README.md
index 60685a4..b75bb74 100644
--- a/languages/README.md
+++ b/languages/README.md
@@ -1,6 +1,6 @@
 # Internationalization (i18n)
 
-You can use internationalization to present your site in different languages. The default language is set by modifying the `language` setting in `_config.yml`. You can also set multiple languages and modify the order of default languages.
+You can use internationalization to present your site in different languages. The default language is set by modifying the `language` setting in Hexo `_config.yml`. You can also set multiple languages and modify the order of default languages.
 
 ```yaml
 language: en
@@ -8,7 +8,7 @@ language: en
 
 ```yaml
 language:
-  - zh-cn
+  - zh-CN
   - en
 ```