diff --git a/html/index.html b/html/index.html
index 3e1696b1..6402285b 100644
--- a/html/index.html
+++ b/html/index.html
@@ -396,6 +396,7 @@ button.danger{background:var(--bad);color:#fff;border-color:transparent}
               <option value="en">English</option>
               <option value="ja">日本語</option>
               <option value="zh">中文</option>
+              <option value="es">Español</option>
             </select></label>
           <label class="row"><span class="lb" data-i18n="sy_theme">Theme</span>
             <select class="in" id="themeSel">