diff --git a/src/index.js b/src/index.js
index 77fcd5a8d161b291842eb94cd9df749014d6edb8..9447ec5fffe7b9e70c93d5b64eebff73b93e744a 100644
--- a/src/index.js
+++ b/src/index.js
@@ -31,11 +31,15 @@ class UniID {
     if (uniIDConfig.hasFile('custom-token.js')) {
       this.setInterceptor('customToken', require(uniIDConfig.resolve('custom-token.js')))
     }
+    const fallbackLocale = 'zh-Hans'
     this._i18n = uniCloud.initI18n({
       locale: this._clientInfo.locale,
-      fallbackLocale: 'zh-Hans',
-      messages
+      fallbackLocale,
+      messages: JSON.parse(JSON.stringify(messages))
     })
+    if (!messages[this._i18n.locale]) {
+      this._i18n.setLocale(fallbackLocale)
+    }
   }
 
   setInterceptor (timing, handler) {