diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 57c0485181..cc80e03ac9 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -142,6 +142,7 @@ function App() {
         maxHeight="-webkit-fill-available"
         width="100vw"
         sx={{ overflowX: 'hidden' }}
+        className={`theme-${themeVariant}`}
       >
         <ChatSettingsModal />
         <RouterProvider router={router} />