diff --git a/src/autocomplete/CommandProvider.js b/src/autocomplete/CommandProvider.js
index 34d0110131..fef0544b8a 100644
--- a/src/autocomplete/CommandProvider.js
+++ b/src/autocomplete/CommandProvider.js
@@ -45,10 +45,10 @@ const COMMANDS = [
         command: '/ddg',
         args: '<query>',
         description: 'Searches DuckDuckGo for results',
-    }
+    },
 ];
 
-let COMMAND_RE = /(^\/\w*)/g;
+const COMMAND_RE = /(^\/\w*)/g;
 
 let instance = null;
 
@@ -62,15 +62,15 @@ export default class CommandProvider extends AutocompleteProvider {
 
     async getCompletions(query: string, selection: {start: number, end: number}) {
         let completions = [];
-        let {command, range} = this.getCurrentCommand(query, selection);
+        const {command, range} = this.getCurrentCommand(query, selection);
         if (command) {
-            completions = this.fuse.search(command[0]).map(result => {
+            completions = this.fuse.search(command[0]).map((result) => {
                 return {
                     completion: result.command + ' ',
                     component: (<TextualCompletion
                         title={result.command}
                         subtitle={result.args}
-                        description={ t_(result.description) }
+                        description={ _t(result.description) }
                         />),
                     range,
                 };
@@ -84,8 +84,7 @@ export default class CommandProvider extends AutocompleteProvider {
     }
 
     static getInstance(): CommandProvider {
-        if (instance == null)
-            {instance = new CommandProvider();}
+        if (instance === null) instance = new CommandProvider();
 
         return instance;
     }
diff --git a/src/i18n/strings/zh_Hans.json b/src/i18n/strings/zh_Hans.json
index 1ade4f6487..e219efed6c 100644
--- a/src/i18n/strings/zh_Hans.json
+++ b/src/i18n/strings/zh_Hans.json
@@ -154,4 +154,5 @@
     "The email address linked to your account must be entered.": "必须输入和你账号关联的邮箱地址。",
     "The file '%(fileName)s' exceeds this home server's size limit for uploads": "文件 '%(fileName)s' 超过了此主服务器的上传大小限制",
     "The file '%(fileName)s' failed to upload": "文件 '%(fileName)s' 上传失败"
+    "Guests can't use labs features. Please register.": "游客不能使用实验性功能。请注册。"
 }
diff --git a/src/languageHandler.js b/src/languageHandler.js
index 584a4ef82b..af428d195f 100644
--- a/src/languageHandler.js
+++ b/src/languageHandler.js
@@ -87,10 +87,10 @@ export function getAllLanguageKeysFromJson() {
 }
 
 export function getLanguagesFromBrowser() {
-    if (navigator.languages) return navigator.languages;
-    if (navigator.language) return [navigator.language]
+    if (navigator.languages && navigator.languages.length) return navigator.languages;
+    if (navigator.language) return [navigator.language];
     return [navigator.userLanguage];
-};
+}
 
 /**
  * Turns a language string, normalises it,