diff --git a/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoBackOffice/Default.cshtml b/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoBackOffice/Default.cshtml
index 2804b57b76..7589c76c6f 100644
--- a/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoBackOffice/Default.cshtml
+++ b/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoBackOffice/Default.cshtml
@@ -1,3 +1,4 @@
+@using System.Globalization
 @using Microsoft.Extensions.Options
 @using Umbraco.Cms.Core.Configuration.Models
 @using Umbraco.Cms.Core.Hosting
@@ -17,7 +18,7 @@
 }
 
 <!DOCTYPE html>
-<html lang="en">
+<html lang="@CultureInfo.CurrentCulture.Name">
 <head>
     <base href="@backOfficePath.EnsureEndsWith('/')" />
     <meta charset="UTF-8" />
@@ -114,6 +115,6 @@
     <script type="module" src="@backofficeAssetsPath/apps/app/app.element.js"></script>
 </head>
 <body class="uui-font uui-text" style="margin: 0; padding: 0; overflow: hidden">
-    <umb-app></umb-app>
+    <umb-app culture="@CultureInfo.CurrentCulture.Name"></umb-app>
 </body>
 </html>
diff --git a/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoInstall/Index.cshtml b/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoInstall/Index.cshtml
index e1352fb2b1..021fbeada9 100644
--- a/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoInstall/Index.cshtml
+++ b/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoInstall/Index.cshtml
@@ -1,3 +1,4 @@
+@using System.Globalization
 @using Microsoft.Extensions.Options
 @using Umbraco.Cms.Core.Configuration.Models
 @using Umbraco.Cms.Core.Hosting
@@ -17,7 +18,7 @@
 }
 
 <!DOCTYPE html>
-<html lang="en">
+<html lang="@CultureInfo.CurrentCulture.Name">
 <head>
     <base href="@backOfficePath.EnsureEndsWith('/')" />
     <meta charset="UTF-8" />
diff --git a/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoLogin/Index.cshtml b/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoLogin/Index.cshtml
index 649b771251..bb179dc23a 100644
--- a/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoLogin/Index.cshtml
+++ b/src/Umbraco.Cms.StaticAssets/umbraco/UmbracoLogin/Index.cshtml
@@ -1,8 +1,9 @@
+@using System.Globalization
 @model Umbraco.Cms.Api.Management.BackOfficeLoginModel
 @addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers
 
 <!DOCTYPE html>
-<html lang="en">
+<html lang="@CultureInfo.CurrentCulture.Name">
     <head>
         <meta charset="UTF-8" />
         <link rel="icon" type="image/svg+xml" href="~/umbraco/login/favicon.svg" />
