diff --git a/static/webui/index.html b/static/webui/index.html
index 6f73c711..e27a823a 100644
--- a/static/webui/index.html
+++ b/static/webui/index.html
@@ -1,6 +1,11 @@
 <!doctype html>
-<html lang="en" data-bs-theme="dark">
+<html lang="en">
 <head>
+    <script>
+        // Set theme early to prevent flash of incorrect style
+        const theme = localStorage.getItem("theme") || "dark";
+        document.documentElement.setAttribute("data-bs-theme", theme);
+    </script>
     <title>OpenWF WebUI</title>
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <link rel="stylesheet" href="/webui/libs/bootstrap.min.css" />
