diff --git a/client/vite.config.ts b/client/vite.config.ts
index c1e650b..60635be 100644
--- a/client/vite.config.ts
+++ b/client/vite.config.ts
@@ -32,8 +32,22 @@ export default defineConfig({
     port: 5173,
     proxy: {
       '/api': serverTarget,
-      '/admin': serverTarget,
       '/healthz': serverTarget,
+      // NOT a bare '/admin' prefix: that would also swallow the /admin and
+      // /admin.html *page* requests themselves (and, since Vite's proxy
+      // matches by string prefix, they do — '/admin' matches '/admin.html'
+      // too), forwarding them to the backend instead of letting Vite serve
+      // its own dev-mode admin.html. In dev the backend only has a stale
+      // production build to fall back on (or nothing, if `client` was never
+      // built), so the page ends up loaded with hashed prod asset paths that
+      // don't exist in Vite's dev module graph — Vite's dev server then
+      // answers those with its SPA-fallback HTML instead of JS, which is
+      // exactly the "wrong MIME type" / NS_ERROR_CORRUPTED_CONTENT failure
+      // reported for the admin page. Only the backend-owned endpoints need
+      // to cross the proxy.
+      '/admin/api': serverTarget,
+      '/admin/login': serverTarget,
+      '/admin/logout': serverTarget,
     },
   },
 });