diff --git a/web/index.html b/web/index.html
index 100d9fb..9437c34 100644
--- a/web/index.html
+++ b/web/index.html
@@ -15,13 +15,6 @@
 
 <body>
   <div id="root"></div>
-  <script>
-    globalThis.__publicField = function(obj, key, value) {
-      Object.defineProperty(obj, typeof key !== 'symbol' ? key + '' : key, {
-        configurable: true, enumerable: true, writable: true, value: value
-      });
-    };
-  </script>
   <script type="module" src="/src/main.tsx"></script>
 </body>
 
diff --git a/web/vite.config.ts b/web/vite.config.ts
index 0e21f22..d7dc4fd 100644
--- a/web/vite.config.ts
+++ b/web/vite.config.ts
@@ -5,12 +5,6 @@ import { resolve } from 'path';
 
 // https://vitejs.dev/config/
 export default defineConfig({
-  define: {
-    // Some pre-compiled npm packages use __publicField (a TypeScript/esbuild helper)
-    // without bundling it. Rewrite bare references to a globalThis property that
-    // we polyfill in index.html before any module code runs.
-    '__publicField': 'globalThis.__publicField',
-  },
   plugins: [
     react(),
     TanStackRouterVite(),
@@ -26,6 +20,16 @@ export default defineConfig({
     setupFiles: ['./src/test/setup.ts'],
     css: true,
   },
+  optimizeDeps: {
+    esbuildOptions: {
+      // maplibre-gl v5 distributes bundles that reference __publicField and
+      // other esbuild class-field helpers without defining them. Setting
+      // target to esnext tells esbuild to emit native class fields instead
+      // of helper-based transforms, which avoids the missing-symbol error.
+      // See: https://github.com/maplibre/maplibre-gl-js/issues/6680
+      target: 'esnext',
+    },
+  },
   server: {
     port: 5747,
     proxy: {
@@ -36,7 +40,8 @@ export default defineConfig({
     },
   },
   build: {
+    target: 'esnext',
     outDir: 'dist',
     emptyOutDir: true,
   },
-});
\ No newline at end of file
+});
