diff --git a/stylesheets/_variables.scss b/stylesheets/_variables.scss
index bd0b5b5a8..a46089d13 100644
--- a/stylesheets/_variables.scss
+++ b/stylesheets/_variables.scss
@@ -1,9 +1,11 @@
 // Copyright 2015-2021 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
-$inter: Inter, 'Helvetica Neue', 'Source Sans Pro', 'Source Han Sans SC',
-  'Source Han Sans CN', 'Hiragino Sans GB', 'Hiragino Kaku Gothic',
-  'Microsoft Yahei UI', Helvetica, Arial, sans-serif;
+$inter: Inter, 'Helvetica Neue', 'Source Sans Pro', 'SF Pro JP',
+  'Hiragino Kaku Gothic Pro', 'ヒラギノ角ゴ Pro W3', メイリオ, Meiryo,
+  'ＭＳ Ｐゴシック', 'Source Han Sans SC', 'Source Han Sans CN',
+  'Hiragino Sans GB', 'Microsoft Yahei UI', 'Helvetica Neue', Helvetica, Arial,
+  sans-serif;
 
 // -- V3 Colors
 
diff --git a/ts/background.ts b/ts/background.ts
index 34f1ddb26..6e1077518 100644
--- a/ts/background.ts
+++ b/ts/background.ts
@@ -500,6 +500,11 @@ export async function startApp(): Promise<void> {
 
   window.document.title = window.getTitle();
 
+  document.documentElement.setAttribute(
+    'lang',
+    window.getLocale().replace('_', '-')
+  );
+
   KeyChangeListener.init(window.textsecure.storage.protocol);
   window.textsecure.storage.protocol.on('removePreKey', (ourUuid: UUID) => {
     const uuidKind = window.textsecure.storage.user.getOurUuidKind(ourUuid);